combust vs blow out

combust and blow out both are verbs.

Word	Noun	Adjective	Verb	Adverb
combust	No	No	Yes	No
blow out	No	No	Yes	No

As verbs, blow out is a hyponym of combust; that is, blow out is a word with a more specific, narrower meaning than combust:

Other hyponyms of combust include catch, light up.

combust (verb)	blow out (verb)
undergo combustion	melt, break, or become otherwise unusable
get very angry and fly into a rage	put out, as of fires, flames, or lights
cause to become violent or angry	erupt in an uncontrolled manner
start to burn or burst into flames
cause to burn or combust