1. thin or slender in form, as a thread.
  2. lacking a sound basis, as reasoning; unsubstantiated; weak: a tenuous argument.
  3. thin in consistency; rare or rarefied.
  4. of slight importance or significance; unsubstantial: He holds a rather tenuous position in history.
  5. lacking in clarity; vague: He gave a rather tenuous account of his past life.

Origin of tenuous

First recorded in 1590–1600; tenu(ity) + -ous
Related formsten·u·ous·ly, adverbten·u·ous·ness, nounun·ten·u·ous, adjectiveun·ten·u·ous·ly, adverbun·ten·u·ous·ness, noun

Synonyms for tenuous

Antonyms for tenuous

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for untenuous


  1. insignificant or flimsya tenuous argument
  2. slim, fine, or delicatea tenuous thread
  3. diluted or rarefied in consistency or densitya tenuous fluid
Derived Formstenuity (tɛˈnjʊɪtɪ) or tenuousness, nountenuously, adverb

Word Origin for tenuous

C16: from Latin tenuis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for untenuous



1590s, irregularly formed from Latin tenuis "thin," from PIE root *ten- "to stretch" (cf. Sanskrit tanuh "thin," literally "stretched out;" see tenet) + -ous. The correct form with respect to the Latin is tenuious. The sense of "having slight importance, not substantial" is found from c.1817.

Online Etymology Dictionary, © 2010 Douglas Harper