| 释义 |
pentagon, a. and n. Geom.|ˈpɛntəgən|
Also 7 -one.
[In A, ad. L. pentagōn-us, a. Gr. πεντάγων-ος pentagonal, five-cornered, f. πεντα- penta- + -γων-ος from stem of γωνία angle. In B, ad. L. pentagōn-um, Gr. πεντάγωνον, the neuter adj. used as n. Cf. F. pentagone n. (13th c. in Littré), whence the Eng. form in -gone.]
†A. adj. Having five angles; pentagonal. Obs. (or regarded as attrib. use of the n.).
1570Billingsley Euclid iv. xi. 118 In a circle geuen to describe a Pentagon figure equilater and equiangle. 1660Barrow Euclid iv. xi, A Pentagone figure. 1669Staynred Fortification 11 The Front A K in the Pentagon Fort.
B. n.
1. a. A figure, usually a plane rectilineal figure, having five angles and five sides. In Fortif. A fort with five bastions.
1571Digges Pantom., Math. Treat. Def. ix. T ij, Euery equilater triangle, square, or Pentagonum. 1650R. Stapylton Strada's Low C. Warres vii. 41 A Fort..built in the forme of a Pentagon. 1660Barrow Euclid iv. xii, About a circle given to describe an equilateral and an equiangular pentagone. 1760Gray Notes Walpole Wks. 1843 V. 201 A man..holding a pair of compasses, and by his side a Polyedron, made up of twelve pentagons. 1800Asiatic Ann. Reg., Misc. Tracts 214/2 The castle of Belgica; an old pentagon with round towers at the angles. 1870Illustr. Lond. News 29 Oct. 446/2 The fort is built in a pentagon.
b. Comb. ˈpentagon-dodecaˈhedron, a dodecahedron contained by twelve pentagons.
1895Story-Maskelyne Crystallogr. §183 The pentagon-dodecahedron approximates..to the regular dodecahedron of geometry in proportion as the dihedral angles..approach equality... The regular dodecahedron.., impossible as a crystallographic form, is the limiting figure between the two classes of pentagon-dodecahedra.
2. (With capital initial.) The name given to a pentagonal building in Washington, D.C., the headquarters of the U.S. Department of Defense. Hence used allusively for the U.S. military leadership.
1945Amer. N. & Q. July 54/1 (heading) Pentagon pip: an affliction common among Army officers and enlisted men stationed in Washington; brought on by an Army order proposing overseas duty for men whose war work has kept them heretofore in the United States. 1951Business Week 29 Dec. 40 To help answer this recurring question the Pentagon set up its own watchdog—the Industrial Relations Division of Assistant Secretary Anna Rosenberg's office. 1952Brewer's Dict. Phr. & Fable (rev. ed.) 697/2 Pentagon.., a vast five-sided building erected in Washington, D.C., to house government officials. It is said to be so great that newcomers who leave their offices never find them again. 1952Observer 30 Nov. 5/4 The Pentagon, that immense monument to modern man's subservience to the desk. 1957Listener 24 Oct. 664/3 The Pentagon hoped that Seato would produce a maximum morale-building effect with minimum demands on the American armed forces. 1959Ibid. 4 June 972/2 The converting of Iran into a United States rocket ordnance depot is an integral part of the Pentagon plan. 1964M. McLuhan Understanding Media v. 51 Life at the Pentagon has been greatly complicated by jet travel. 1972A. Price Col. Butler's Wolf xiii. 142 The students didn't approve of the Kremlin any more than the Pentagon. 1974Jrnl. Politics XXXVI. 82 In cases where appropriations had been provided to cover broad categories, the Defense Department should keep faith with the committee and with Congress by adhering to the detailed justifications presented in support of the Pentagon's budget. 1976H. MacInnes Agent in Place ix. 85 The Pentagon might start investigating its own security. |