swimming vs plunge

swimming and plunge both are nouns.

Word	Noun	Adjective	Verb	Adverb
swimming	Yes	Yes	No	No
plunge	Yes	No	Yes	No

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

Other hyponyms of swimming include bathe, skinny-dip, dip, dive, diving, floating, natation, skin-dive, skin diving.

swimming (noun)	plunge (noun)
the act of swimming	a brief swim in water
	a steep and rapid fall

swimming (adjective)	plunge (adjective)
applied to a fish depicted horizontally
filled or brimming with tears

swimming (verb)	plunge (verb)
	begin with vigor
	devote (oneself) fully to
	cause to be immersed
	immerse briefly into a liquid so as to wet, coat, or saturate
	thrust or throw into
	fall abruptly
	drop steeply
	dash violently or with great speed or impetuosity