Plaintive means sounding sad and full of complaint. A plaintive cry, plaintive music, plaintive voice.
It is about sound almost always, so a plaintive look is a stretch where a plaintive note is not. The complaint in it is mournful rather than angry. It shares its root with plaintiff, the person bringing a complaint to court.
1adjectiveplaintiveSounding sad and full of complaint.
“The kitten gave a plaintive meow outside the locked door.”
plaintive is a quality of sound.
Old French pleintif means lamenting, from plainte, a lament, from Latin plangere, to beat the breast in grief. Plaintiff is the same word.
Old French
pleintif — aggrieved, lamenting
Middle English
pleintif
English, today
plaintive
Built from
From Middle English pleintif, plentyff, from Old French pleintif (“aggrieved, lamenting”) (whence modern French plaintif), from plainte (“lament, complaint”); see plaint. a doublet of plaintiff.
Etymology from Wiktionary, CC BY-SA