Divine party with someone on vacation (5)
I believe the answer is:
dowse
'divine' is the definition.
(I've seen this before)
'party with someone on vacation' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'with' becomes 'w' (short for with).
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'someone' with its centre removed is 'se'.
'do'+'w'+'se'='DOWSE'
(Other definitions for dowse that I've seen before include "try to find water" , "put fire out" , "Search for water using hazel twig" , "Use a divining rod" , "twitch" .)