- tenuous (adj.)
- 1590s, "thin, unsubstantial," irregularly formed from Latin tenuis "thin, drawn out, meager, slim, slender," figuratively "trifling, insignificant, poor, low in rank," from PIE root *ten- "to stretch" (source also of Sanskrit tanuh "thin," literally "stretched out;" see tenet) + -ous. The correct form with respect to the Latin is tenuious. The figurative sense of "having slight importance, not substantial" is found from 1817 in English. Related: Tenuously; tenuousness.
