imminent vs impending

imminent and impending both are adjectives.

Word	Noun	Adjective	Verb	Adverb
imminent	No	Yes	No	No
impending	No	Yes	No	No

As adjectives, imminent and impending are synonyms defined as:

Other synonyms of imminent include at hand, close at hand, impendent.

imminent (adjective)	impending (adjective)
close in time; about to occur	close in time; about to occur