popularize vs circularize

popularize and circularize both are verbs.

Word	Noun	Adjective	Verb	Adverb
popularize	No	No	Yes	No
circularize	No	No	Yes	No

As verbs, circularize is a hypernym of popularize; that is, circularize is a word with a broader meaning than popularize:

popularize: cater to popular taste to make popular and present to the general public; bring into general or common use
circularize: cause to become widely known

popularize (verb)	circularize (verb)
make understandable to the general public	make circular
cater to popular taste to make popular and present to the general public; bring into general or common use	cause to become widely known
	distribute circulars to
	canvass by distributing letters
	canvass by using a questionnaire