c. 1600, "transitory, not durable," from Latin transientem (nominative transiens) "passing over or away," present participle of transire "cross over, go over, pass over, hasten over, pass away," from trans "across, beyond" (see trans-) + ire "to go" (from PIE root *ei- "to go"). Meaning "passing through a place without staying" is from 1680s. The noun is first attested 1650s; specific sense of "transient guest or boarder" attested from 1857. Related: Transiently.
