maxim

Etymology 1

From Anglo-Norman maxime and Middle French maxime, from Late Latin maxima (“axiom”), noun use of the feminine singular form of Latin maximus (apparently as used in the phrase prōpositiō maxima (“greatest premise”)). Doublet of maxima.

noun

1. (now rare) A self-evident axiom or premise; a pithy expression of a general principle or rule.
2. A precept; a succinct statement or observation of a rule of conduct or moral teaching.
   In every age and country of the world men must have attended to the characters, designs, and actions of one another, and many reputable rules and maxims for the conduct of human life, must have been laid down and approved of by common consent. 1776, Wealth of Nations, archived from the original on 2008-06-26, page 768

Etymology 2

From Sir Hiram Maxim

noun

1. Alternative letter-case form of Maxim