Wreck drink almost entirely (5)
I believe the answer is:
total
'wreck' is the definition.
(thesaurus)
'drink almost entirely' is the wordplay.
'drink' becomes 'tot' (I've seen this before**).
'almost' means to remove the last letter (most of the word but not all of it).
'entirely' becomes 'all' (I've seen this before).
'all' with its last letter taken off is 'al'.
'tot'+'al'='TOTAL'
(Other definitions for total that I've seen before include "Completely destroy" , "given by 8 [ADDING MACHINES]" , "Whole, complete" , "Complete sum" , "Entirety" .)