verb
thrashes; thrashed; thrashing
[+ obj] :to hit (someone or something) very hard with a stick, whip, etc.
[+ obj] informal :to defeat (someone or something) very easily or completely
[no obj] :to move about violently
thrash out
[phrasal verb]
thrash (something) out or thrash out (something) :to talk about (something) in order to make a decision, find a solution, etc.
noun
plural thrashes
[noncount] :a type of rock music that is very fast and loud
[singular] :a violent movement
[count] Brit informal + old-fashioned :a party with loud music and dancing