Throw out bad nephews after loss of hen (4)
I believe the answer is:
spew
'throw out' is the definition.
(thesaurus)
'bad nephews after loss of hen' is the wordplay.
'bad' indicates anagramming the letters.
'after loss of' indicates named letters should be taken away.
'nephews' with 'hen' taken out is 'pews'.
'pews' anagrammed gives 'SPEW'.
(Other definitions for spew that I've seen before include "Erupt, eject" , "Spit or stream out" , "bring it up" , "Cast out in a stream, vomit" , "Expel" .)