1520s, "concise statement of a principle" (especially in reference to the "Aphorisms of Hippocrates"), from French aphorisme (corrected from Old French aufforisme, 14c.), from Late Latin aphorismus, from Greek aphorismos "definition; short, pithy sentence," from aphorizein "to mark off, divide," from apo "from" (see apo-) + horizein "to bound" (see horizon).

The term aphorism is derived from the Greek aphorismos, meaning “definition.” Greek physician Hippocrates coined the word and wrote a book on medical aphorisms.

aphorism a concise statement of a scientific principle, typically by a classical author; a pithy observation which contains a general truth. The word comes from the ‘Aphorisms of Hippocrates ’, and was transferred to other sententious statements of the principles of physical science, and then to statements of principles generally.