n. 1
Moral rule or aspect.
I don't doubt your principles.
n. 2
A source, or origin; that from which anything proceeds; fundamental substance or energy; primordial substance; ultimate element, or cause.
n. 3
A fundamental assumption, fundamental law or guiding belief.
We need some sort of principles to reason from.
n. 4
A rule used to choose among solutions to a problem.
The principle of least privilege holds that a process should only receive the permissions it needs.

Related words

Word family: principled prince principal principality
Phrases: verifiability principle superposition principle dormitive principle extractive principle non-aggression principle principle of contradiction principle of substitutivity principle of verifiability

Forms

Principle, Doctrine or Teaching?

Doctrine primarily signifies that which is taught; principle, the fundamental basis on which the teaching rests.

J. C. Fernald, English Synonyms and Antonyms (1914)

Use in printed books, per decade from 1850 to 2019.

3 letters: law¹
4 letters: rule¹
5 letters: cause¹, value², truth¹, maxim², dogma², tenet², axiom³
6 letters: reason², ground¹, source¹, spring¹, spirit², belief², origin³, motive²
7 letters: formula³, element³, honesty³, premise², precept², probity³
8 letters: position³, doctrine², keystone², rudiment³
9 letters: integrity⁴, substance², rationale³, postulate³, rectitude³
10 letters: regulation⁴, conscience², substratum, mainspring, hypostasis
11 letters: uprightness

The small number after each word is its number of syllables (value² = 2 syllables).