Yule log vs backlog

Yule log and backlog both are nouns.

Word	Noun	Adjective	Verb	Adverb
Yule log	Yes	No	No	No
backlog	Yes	No	Yes	No

As nouns, backlog is a hypernym of Yule log; that is, backlog is a word with a broader meaning than Yule log:

Yule log (noun)	backlog (noun)
large log traditionally burned at Christmas	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

Yule log (verb)	backlog (verb)
	accumulate and create a backlog