unceasing vs incessant

unceasing and incessant both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unceasing	No	Yes	No	No
incessant	No	Yes	No	No

As adjectives, unceasing and incessant are synonyms defined as:

unceasing and incessant: uninterrupted in time and indefinitely long continuing

Other synonyms of unceasing include ceaseless, constant, never-ending, perpetual, unremitting.

unceasing (adjective)	incessant (adjective)
uninterrupted in time and indefinitely long continuing	uninterrupted in time and indefinitely long continuing
continuing forever or indefinitely