diffuse vs spread out

diffuse is an adjective but spread out is not an adjective.

Word	Noun	Adjective	Verb	Adverb
diffuse	No	Yes	Yes	No
spread out	No	No	Yes	No

As verbs, diffuse and spread out are synonyms defined as:

Other synonyms of diffuse include fan out, spread.

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

diffuse (verb)	spread out (verb)
cause to become widely known	set out or stretch in a line, succession, or series
spread or diffuse through	spread out or open from a closed or folded state
move outward	move outward
	extend in one or more directions
	move away from each other
	turn outward
	strew or distribute over an area