thrashing vs beating

thrashing and beating both are nouns.

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

As nouns, thrashing and beating are synonyms defined as:

thrashing and beating: the act of inflicting corporal punishment with repeated blows

Other synonyms of thrashing include drubbing, lacing, licking, trouncing, whacking.

thrashing (noun)	beating (noun)
the act of inflicting corporal punishment with repeated blows	the act of inflicting corporal punishment with repeated blows
a sound defeat	the act of overcoming or outdoing