diffuse vs popularise

diffuse is an adjective but popularise is not an adjective.

Word	Noun	Adjective	Verb	Adverb
diffuse	No	Yes	Yes	No
popularise	No	No	Yes	No

As verbs, popularise is a hyponym of diffuse; that is, popularise is a word with a more specific, narrower meaning than diffuse:

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

Other hyponyms of diffuse include podcast, sow, generalise, generalize, popularize, vulgarise, vulgarize, carry, run.

diffuse (adjective)	popularise (adjective)
(of light) transmitted from a broad light source or reflected
spread out; not concentrated in one place
lacking conciseness

diffuse (verb)	popularise (verb)
cause to become widely known	make understandable to the general public
spread or diffuse through	cater to popular taste to make popular and present to the general public; bring into general or common use
move outward