backlog vs amass

backlog is a noun but amass is not a noun.

Word	Noun	Adjective	Verb	Adverb
backlog	Yes	No	Yes	No
amass	No	No	Yes	No

As verbs, amass is a hypernym of backlog; that is, amass is a word with a broader meaning than backlog:

Other hypernyms of backlog include accumulate, conglomerate, cumulate, gather, pile up.

backlog (noun)	amass (noun)
an accumulation of jobs not done or materials not processed that are yet to be dealt with (especially unfilled customer orders for products or services)
something kept back or saved for future use or a special purpose
the large log at the back of a hearth fire

backlog (verb)	amass (verb)
accumulate and create a backlog	increase in amount by collecting or gathering
	get or gather together