See pal drunk when out for the night (6)
I believe the answer is:
asleep
'out for the night' is the definition.
(I've seen this in another clue)
'see pal drunk' is the wordplay.
'drunk' is an anagram indicator.
'see'+'pal'='seepal'
'seepal' anagrammed gives 'ASLEEP'.
'when' acts as a link.
(Other definitions for asleep that I've seen before include "Please be at rest (6)." , "coiled up?" , "like a kipper" , "Like kippers" , "Dormant; inattentive" .)