1. Lamenting; complaining; giving utterance to sorrow or grief; repining.Expressive of sorrow or melancholy; mournful; sad: said of things: as, a plaintive sound; a plaintive air; a plaintive song.Synonyms Plaintive, Querulous, woful, rueful. Plaintive and querulous agree in expressing weakness. He who is querulous is ready to find fault over trivial matters, and in a weak, captious, tired way; there is a tone recognized as querlous. Plaintive is rarely said of persons; a plaintive tone or utterance conveys a subdued regret or lamentation : as, the plaintive note of the mourning dove. See petulant.