thrashing vs lashing

thrashing and lashing both are nouns.

Word	Noun	Adjective	Verb	Adverb
thrashing	Yes	No	No	No
lashing	Yes	Yes	No	No

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

Other hyponyms of thrashing include flagellation, flogging, tanning, whipping, flagellation.

thrashing (noun)	lashing (noun)
the act of inflicting corporal punishment with repeated blows	beating with a whip or strap or rope as a form of punishment
a sound defeat	rope that is used for fastening something to something else

thrashing (adjective)	lashing (adjective)
	violently urging on by whipping or flogging