Hangover cure (4,2,3,3)
I believe the answer is:
hair of the dog
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">hangover cure</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for hair of the dog that I've seen before include "may cover boxer" , "Maybe one in the morning" , "Alcohol as hangover cure (colloq.)" , "Morning tipple after night of excessive drinking" , "'...that bit one' completes a dubious hangover remedy" .)