[Middle English, from Old French sententieux, from Latin sententiōsus, full of meaning, from sententia, opinion; see sentence.] sen·ten'tious·ly adv., sen·ten'tious·ness n.
1440, "full of meaning," from M.Fr. sententieux, from L. sententiosus "full of meaning, pithy," from sententia "opinion, maxim" (see sentence). Meaning "addicted to pompous moralizing" first recorded 1598.