jiffy vs moment

jiffy and moment both are nouns.

Word	Noun	Adjective	Verb	Adverb
jiffy	Yes	No	No	No
moment	Yes	No	No	No

As nouns, moment is a hypernym of jiffy; that is, moment is a word with a broader meaning than jiffy:

jiffy: a very short time (as the time it takes the eye to blink or the heart to beat)
moment: an indefinitely short time

Other hypernyms of jiffy include bit, minute, mo, second.

jiffy (noun)	moment (noun)
a very short time (as the time it takes the eye to blink or the heart to beat)	having important effects or influence
	the n-th moment of a distribution is the expected value of the n-th power of the deviations from a fixed value
	a turning force produced by an object acting at a distance (or a measure of that force)
	a particular point in time
	an indefinitely short time
	at this time