bomb vs bomb out

bomb is a noun but bomb out is not a noun.

Word	Noun	Adjective	Verb	Adverb
bomb	Yes	No	Yes	No
bomb out	No	No	Yes	No

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

bomb (noun)	bomb out (noun)
an explosive device fused to explode under specific conditions
strong sealed vessel for measuring heat of combustion
an event that fails badly or is totally ineffectual

bomb (verb)	bomb out (verb)
throw bombs at or attack with bombs	make somebody homeless by destroying their houses with bombs
fail to get a passing grade