principle /prinˈsi-pl/

1. A source, root, origin
2. A fundamental or primary cause
3. A beginning (obsolete)
4. Essential nature
5. A theoretical basis or assumption from which to argue, etc
6. An instinct or natural tendency (as in the pleasure principle), or a faculty of the mind
7. A source of action
8. A scientific law, esp as explaining a natural phenomenon or the way a machine works
9. A fundamental truth on which others are founded or from which they spring
10. A law or doctrine from which others are derived
11. A general rule that guides one's (moral) conduct
12. Consistent regulation of behaviour according to moral law
13. The morality or moral aspect of eg a policy or course of action
14. A norm of procedure (as in the principle of first come first served)
15. A component (obsolete)
16. A constituent of a substance that gives it its distinctive character (chem)
17. Motive power or the source of it (Milton)

1. To ground in principles
2. To impress a doctrine on

prinˈcipled adjective

1. Holding certain principles
2. Having, or behaving in accordance with, good principles
3. Invoking or founded on a principle

principle of contradiction noun

The logical principle that a thing cannot both be and not be

principle of equivalence noun

A statement of the theory of relativity, shown by an observer being unable to distinguish whether the laboratory is in a uniform gravitational field or in an accelerated frame of reference

principle of least time noun

A statement that the path of a ray, eg of light, from one point to another will be that taking the least time (also Fermat's principle of least time)

principle of relativity noun

A universal law of nature stating that the laws of mechanics are not affected by a uniform rectilinear motion of the system of co-ordinates to which they are referred (see also relativity under relate)

principle of sufficient reason see under reason

principle of the excluded middle noun (logic)

The principle that a thing must be either one thing or its contradictory

first principles

Fundamental principles, not deduced from others

in principle

1. So far as general character or theory is concerned without respect to details or particular application
2. Broadly or basically
3. In theory

on principle

1. On grounds of (moral) principle
2. For the sake of obeying or asserting a particular principle of morality or wisdom

• omoplates
• omoplatoscopies
• omoplatoscopy
• OMOV
• omphacite
• omphacites
• omphali
• omphalic
• omphaloid
• omphalomancies
• omphalomancy
• omphalos
• OMR
• omrah
• omrahs
• oms
• o' my conscience
• -on
• on
• on-
• ON
• on account
• on account of
• onager
• onagers