plaintive (adj) – Expressing sorrow; mournful.
Source : The Free Dictionary
Etymology : Like its relative plangent, plaintive is often used to describe sad sounds. “A plaintive wail,” for example, is a common use. Plaintive and plangent (along with relatives plaintiff and complain) ultimately derive from the Latin verb plangere, meaning “to strike,” “to beat one’s breast,” or “to lament.” This Latin verb led to plaint , an Anglo-French word (and now also an English word) meaning “lamentation.” Plaint is the root of Middle English plaintif (meaning “lamenting” or “complaining”), which gave rise to plaintive as well as the noun plaintiff.