An Etymological Dictionary of Astronomy and Astrophysics

1. Of very little importance or value; insignificant; commonplace; ordinary.
   

2a) Math.: A solution of an equation in which the value of every variable of the equation is equal to zero. For example, x² + 2y² = x + 3y has a trivial solution x = 0, y = 0.

2b) Of a theorem or proof: simple, transparent, or immediately evident.

Any theorem once a proof has been obtained, no matter how difficult the theorem was to prove in the beginning.

2c) For any natural number, the number itself and 1 which are called trivial divisors.

3. Chemistry: → trivial name.

Etymology (EN): From M.L. trivialis “found everywhere, commonplace; known by every body,” from trivium literally “crossroad, a place where three roads meet,” also “the lower division of the seven liberal arts taught in medieval universities, i.e. grammar, rhetoric, and logic,” from tri-, → three, + via “road,” since it was common in Roman Empire for three roads to meet.

Etymology (PE): Zab “easy, unbought, gratis; straight,” variant zap, related to sabok “light, not heavy; unsteady;” Proto-Iranian *θrap-/tarp- “to be unsteady;” cf. Kurd. terpin “to stumble;” Pashto drabəl “to shake, press down;” Skt. trepa- “hasty;”
Gk. trepein “to turn;” L. trepidus “agitated, anxious;” PIE *trep- “to shake, tremble.”