Ignore an interlude by getting drunk (4,1,5,3)
I believe the answer is:
turn a blind eye
'ignore' is the definition.
(I've seen this before)
'an interlude by getting drunk' is the wordplay.
'getting drunk' indicates an anagram.
'an'+'interlude'+'by'='aninterludeby'
'aninterludeby' with letters rearranged gives 'TURN A BLIND EYE'.
(Other definitions for turn a blind eye that I've seen before include "pay no attention" , "Pretend not to have seen" , "Overlook deliberately" , "Disregard deliberately" , "take no notice" .)