ambiguity vs loophole

ambiguity and loophole both are nouns.

Word	Noun	Adjective	Verb	Adverb
ambiguity	Yes	No	No	No
loophole	Yes	No	No	No

As nouns, loophole is a hyponym of ambiguity; that is, loophole is a word with a more specific, narrower meaning than ambiguity:

ambiguity: an expression whose meaning cannot be determined from its context
loophole: an ambiguity (especially one in the text of a law or contract) that makes it possible to evade a difficulty or obligation

Other hyponyms of ambiguity include amphibology, amphiboly, parisology, double entendre.

ambiguity (noun)	loophole (noun)
unclearness by virtue of having more than one meaning	a small hole in a fortified wall; for observation or discharging weapons
an expression whose meaning cannot be determined from its context	an ambiguity (especially one in the text of a law or contract) that makes it possible to evade a difficulty or obligation