bombing vs bombing run

bombing and bombing run both are nouns.

Word	Noun	Adjective	Verb	Adverb
bombing	Yes	No	No	No
bombing run	Yes	No	No	No

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

bombing: an attack by dropping bombs
bombing run: that part of the flight that begins with the approach to the target; includes target acquisition and ends with the release of the bombs

Other hyponyms of bombing include area bombing, carpet bombing, saturation bombing.

bombing (noun)	bombing run (noun)
an attack by dropping bombs	that part of the flight that begins with the approach to the target; includes target acquisition and ends with the release of the bombs
the use of bombs for sabotage; a tactic frequently used by terrorists