bomber vs dive bomber

bomber and dive bomber both are nouns.

Word	Noun	Adjective	Verb	Adverb
bomber	Yes	No	No	No
dive bomber	Yes	No	No	No

As nouns, dive bomber is a hyponym of bomber; that is, dive bomber is a word with a more specific, narrower meaning than bomber:

bomber: a military aircraft that drops bombs during flight
dive bomber: a bomber that releases its bombs during a steep dive toward the target

Other hyponyms of bomber include stealth bomber.

bomber (noun)	dive bomber (noun)
a military aircraft that drops bombs during flight	a bomber that releases its bombs during a steep dive toward the target
a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States
a person who plants bombs