aphorism (n.) Look up aphorism at Dictionary.com
1520s (especially in reference to the "Aphorisms of Hippocrates"), from Middle French aphorisme (14c., aufforisme), from Late Latin aphorismus, from Greek aphorismos "definition, pithy sentence," from aphorizein "to mark off, divide," from apo- "from" (see apo-) + horizein "to bound" (see horizon).

An aphorism is a short, pithy statement containing a truth of general import; an axiom is a statement of self-evident truth; a theorem is a demonstrable proposition in science or mathematics; an epigram is like an aphorism, but lacking in general import. Maxim and saying can be used as synonyms for aphorism.