blow up vs billow

blow up is not a noun while billow is a noun.

Word	Noun	Adjective	Verb	Adverb
blow up	No	No	Yes	No
billow	Yes	No	Yes	No

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

Other hyponyms of blow up include reflate, heave, surge.

blow up (noun)	billow (noun)
	a large sea wave

blow up (verb)	billow (verb)
make large	become inflated
exaggerate or make bigger	rise and move, as in waves or billows
to swell or cause to enlarge	rise up as if in waves
cause to burst with a violent release of energy	move with great difficulty
fill with gas or air
burst and release energy as through a violent chemical or physical reaction
add details to
get very angry and fly into a rage