tenuous vs slight

tenuous is not a noun while slight is a noun.

Word	Noun	Adjective	Verb	Adverb
tenuous	No	Yes	No	No
slight	Yes	Yes	Yes	No

As adjectives, tenuous and slight are synonyms defined as:

Other synonyms of tenuous include flimsy, fragile, thin.

tenuous (noun)	slight (noun)
	a deliberate discourteous act (usually as an expression of anger or disapproval)

tenuous (adjective)	slight (adjective)
lacking substance or significance	(quantifier used with mass nouns) small in quantity or degree; not much or almost none or (with `a') at least some
very thin in gauge or diameter	lacking substance or significance
having thin consistency	being of delicate or slender build

tenuous (verb)	slight (verb)
	pay no attention to, disrespect