orbitaladj.n.
/ˈɔːbᵻtl/, U.S. /ˈɔrbədl/ A. adj.
1. Anatomy and Zoology. Of, relating to, connected with, or near the orbit of the eye.
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the world > life > the body > structural parts > bone or bones > skull > parts of skull > [adjective] > socket of eye
orbital?1541
orbitary1703
superciliary1704
orbitar1726
suborbitary1733
infra-orbitar1741
supraorbital1767
supraorbitar1775
supra-orbitary1794
suborbitar1797
suborbital1803
infra-orbital1806
infra-orbitary1822
lachrymonasal1837
interorbital1852
preorbital1852
transorbital1852
orbitosphenoid1854
exorbital1876
periorbital1890
?1541 R. Copland Guy de Chauliac's Questyonary Cyrurgyens ii. sig. Eiij The eyes..are set within the bone arbytall that is a party of the coronall, & the bones of the temples.
1828 J. Stark Elements Nat. Hist. I. 44 The Active Gibbon..forehead very low; orbital arches very prominent.
1878 A. M. Hamilton Nerv. Dis. 168 The anterior lobe of the brain is composed of two divisions, the one inferior, or orbital, formed by the several convolutions called orbital.
1921 S. E. Whitnall Anat. Human Orbit 82 This muscle, described by H. Müller in 1858, is known as the ‘orbital muscle of Müller’, or musculus orbitalis.
1962 V. Nabokov Pale Fire (1963) 173 The crinkly little rays of his orbital flesh bespoke infinite humor.
1995 Nursing Times 22 Mar. 55/1 I still had some left orbital oedema and a ‘black eye’.
2. Of, belonging to, or of the nature of an orbit (orbit n. 2), esp. that of a celestial object; moving or taking place in an orbit or circular path; (also) relating to or designating such motion. Also figurative.
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the world > the universe > heavenly body > movement of heavenly bodies > [adjective] > movement in orbit
periodical1603
periodic1650
revolutional1652
orbitual1806
orbital1846
orbituary1864
orbiting1951
society > travel > air or space travel > space flight > [adjective] > (put) in orbit > moving or taking place in orbit
orbital1949
1846 Ladies' Repository July 214/1 Have they [sc. the planets] a real orbital motion?
1852 P. J. Bailey Festus (ed. 5) 533 Its æras are all cycles; its events, How strange soe'er, are ever orbital.
a1856 D. Lardner Handbk. Astron. II. xvii. 499 The mean orbital velocities of the planets are in the inverse ratio one to another of the square roots of the distances.
1875 B. Stewart & P. G. Tait Unseen Universe (ed. 2) 126 That our earth will gradually lose its orbital energy and approach the sun by a slow spiral motion.
1949 W. Ley Conquest of Space (1950) 48 Probably the manned moonship will have to be postponed until there is an orbital station.
1961 Guardian 6 May 1/4 The Mercury programme itself could be used as a means of sending men into substantially protracted orbital flights.
1987 Spaceflight Oct. 54/1 The real value of the orbital vehicle lies in its importance as an essential springboard in the supreme adventure of interplanetary flight.
2001 Guardian 18 Oct. (Online section) 11/6 The Yarkovsky effect causes a hurry-up of the orbital evolution, and so can explain the brief space exposure ages of meteorites.
3. British. Designating a road, railway, or rail or road system encircling a large town. Cf. ring road n.
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society > travel > means of travel > route or way > [adjective] > in specific direction
cross-town1886
radial1892
orbital1933
1933 Archit. Rev. 74 166/2 Orbital road system around London.
1967 Times Rev. Industry Apr. 50/2 Essential features are good car parking space..and good communications. Orbital roads, motorways and similar positions are popular.
1977 Mod. Railways Dec. 459/3 This would effectively establish one of the north orbital routes discussed in the Barran Committee's London Rail Study three years ago.
2000 Transport Matters (Greater Manchester Transportation Unit) Spring 2/3 The Government's Highways Agency will complete the last bit of the M60 orbital motorway shortly.
B. n.
1. Physics and Chemistry. An actual or potential pattern of electron density around an atomic nucleus or nuclei that may be formed by either one or two electrons in a bound state in an atom or molecule; the wave function of a single electron corresponding to any such pattern.
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the world > matter > chemistry > atomic chemistry > [noun] > electrons > orbitals
orbital1932
MO1937
1932 R. S. Mulliken in Physical Rev. 41 50 From here on, one-electron orbital wave functions will be referred to for brevity as orbitals. The method followed here will be to describe unshared electrons always in terms of atomic orbitals but to use molecular orbitals for shared electrons.
1956 Nature 11 Feb. 275/1 The resultant g values..will yield details on the orbitals involved in the chemical binding of the central iron atom.
1964 J. W. Linnett Electronic Struct. Molecules i. 9 Since each spatial orbital is defined by the three quantum numbers n, l and m, this [sc. the Pauli Principle] is equivalent to saying that each orbital can accommodate two electrons.
1974 D. M. Adams Inorg. Solids ii. 20 In describing bonding in terms of molecular-orbital theory, atomic orbitals are combined to give delocalized molecular orbitals extending over the entire molecule.
1991 Sci. Amer. Oct. 16/3 Nuclei can be considered to have shells, or bunchings of energy levels, that protons and neutrons fill up, much the way electrons fill up orbitals of atoms.
2. An orbital road or railway.
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society > travel > means of travel > route or way > way, path, or track > road > [noun] > for wheeled vehicles > ring road or by-pass
ring road1874
beltline1922
bypass1922
beltway1951
ringway1960
orbital1970
1970 Times 3 Feb. 2 First priority for roads, after the orbitals outside Greater London, is Ringway 2 (North and South Circular Roads).
1975 Country Life 16 Oct. 970 (caption) Near Great Warley. The London Orbital will pass across the fields in the middle distance.
2001 Surveyor May 4/2 The controversial Birmingham Western Orbital has been rejected.
Compounds
C1.
orbital motion n.
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the world > matter > physics > quantum theory > electron shell > [noun] > orbit of electron in atom > movement within
orbital motion1970
1846Orbital motion [see sense A. 2].
1970 G. K. Woodgate Elem. Atomic Struct. iv. 55 A single-electron atom has a magnetic moment associated with the orbital motion of the electron.
1998 Guardian 16 July (Online section) 9/1 Cometariums, which show the orbital motion of a comet around the sun.
orbital revolution n.
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1869 E. Durkin Midnight Sky 274 All this complicated system moves with a common motion so exact that no part interferes with another in their orbital revolution, which is performed in rather less than thirty years.
1990 Science 2 Mar. 1064/3 The Jovian perturbations occurring in the course of one orbital revolution are always weak.
C2.
orbital index n. [after French indice orbitaire (P. Broca 1874, in Mém. d'Anthropol. 2 69)] Physical Anthropology an indicator of the size and shape of the orbit (orbit n. 1), obtained by multiplying the ratio of its width to its height by 100.
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the world > life > the body > structural parts > bone or bones > skull > skull measurement > [noun]
cephalic index1866
index1866
cranial index1868
orbital index1877
1877 Jrnl. Anthropol. Inst. 6 36 (table) Measurements of Cissbury Skeleton... Orbital index..·83 [cubic inches].
1879 tr. A. de Quatrefages de Bréau Human Species xxx. 388 The smallest orbital index known is that of the old man of Cro-Magnon, which we have seen to be 61·36.
1984 Current Anthropol. 25 505/2 The angle between nasal bones and profile line large, and the orbital index lower than average.
orbital quantum number n. Physics (more fully orbital angular momentum quantum number) the quantum number of the angular momentum possessed by an electron or group of electrons by virtue of occupying a particular orbital (symbol l or L; see L n. 6b); also called azimuthal quantum number.
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1929 Proc. Royal Soc. A. 124 170 The general theory must hold for the first approximation, and can therefore be expressed in terms of the orbital quantum numbers.
1949 Proc. Royal Soc. A. 196 138 As S = 0, J = l the orbital angular momentum quantum number, which is thus a true quantum number for the singlet states.
1994 D. F. Shriver et al. Inorg. Chem. (ed. 2) i. 19 Each subshell of a shell is distinguished by a quantum number l called the orbital angular momentum quantum number.
orbital sander n. Joinery an electric sander having a rotating sanding plate.
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1966 Pop. Sci. Jan. 147/1 Fastest orbital sander.
1991 Which? July 412/1 An orbital sander has a flat rectangular sanding plate to which you attach abrasive paper. The plate then vibrates in tiny circles, hence the name.
orbital tower n. Science Fiction and Astronautics a structure linking a planet, moon, etc., with a space station or satellite which is in stationary orbit around it.
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1975 J. Pearson in Acta Astron. 2 785 If a physical connection could be made between the geostationary satellite and the ground, it would allow vertical ascent by powered capsules up this ‘orbital tower’ directly into geostationary orbit.
1979 A. C. Clarke Fountains of Paradise 51 At last we can build the Space Elevator—or the Orbital Tower, as I prefer to call it.
2002 Courier Mail (Brisbane) (Nexis) 10 Aug. M06 No one really expected to find life, though, so it comes as quite a surprise when the crew..observe the overnight creation of orbital towers extending from the planet surface into space.
This entry has been updated (OED Third Edition, September 2004; most recently modified version published online March 2022).
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adj.n.?1541