depth charge vs bomb

depth charge and bomb both are nouns.

Word	Noun	Adjective	Verb	Adverb
depth charge	Yes	No	No	No
bomb	Yes	No	Yes	No

As nouns, bomb is a hypernym of depth charge; that is, bomb is a word with a broader meaning than depth charge:

depth charge: a bomb that explodes at a preset depth under water; antisubmarine device
bomb: an explosive device fused to explode under specific conditions

depth charge (noun)	bomb (noun)
a bomb that explodes at a preset depth under water; antisubmarine device	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

depth charge (verb)	bomb (verb)
	throw bombs at or attack with bombs
	fail to get a passing grade