Mason, thrown out, complains (5)
I believe the answer is:
moans
'complains' is the definition.
(I've seen this before)
'mason thrown out' is the wordplay.
'thrown out' indicates an anagram.
'mason' with letters rearranged gives 'MOANS'.
(Other definitions for moans that I've seen before include "Trivial complaints" , "- - and groans" , "Whinges" , "Grumbles" , "Complains" .)