thrash vs swimming kick

thrash and swimming kick both are nouns.

Word	Noun	Adjective	Verb	Adverb
thrash	Yes	No	Yes	No
swimming kick	Yes	No	No	No

As nouns, swimming kick is a hypernym of thrash; that is, swimming kick is a word with a broader meaning than thrash:

thrash (noun)	swimming kick (noun)
a swimming kick used while treading water	a movement of the legs in swimming

thrash (verb)	swimming kick (verb)
give a thrashing to; beat hard
beat the seeds out of a grain
beat thoroughly and conclusively in a competition or fight
dance the slam dance
move or stir about violently
beat so fast that (the heart's) output starts dropping until (it) does not manage to pump out blood at all
move data into and out of core rather than performing useful computation