heartbeat vs jiffy

heartbeat and jiffy both are nouns.

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

As nouns, heartbeat and jiffy are synonyms defined as:

heartbeat and jiffy: a very short time (as the time it takes the eye to blink or the heart to beat)

Other synonyms of heartbeat include blink of an eye, flash, instant, New York minute, split second, trice, twinkling, wink.

heartbeat (noun)	jiffy (noun)
an animating or vital unifying force	a very short time (as the time it takes the eye to blink or the heart to beat)
the rhythmic contraction and expansion of the arteries with each beat of the heart
a very short time (as the time it takes the eye to blink or the heart to beat)