duck hunting vs ducking

duck hunting and ducking both are nouns.

Word	Noun	Adjective	Verb	Adverb
duck hunting	Yes	No	No	No
ducking	Yes	No	No	No

As nouns, duck hunting and ducking are synonyms defined as:

duck hunting (noun)	ducking (noun)
hunting ducks	the act of wetting something by submerging it
	hunting ducks