Monstrous drunken orgies at hotel (7)
I believe the answer is:
ogreish
'monstrous' is the definition.
(I've seen this before)
'drunken orgies at hotel' is the wordplay.
'drunken' indicates anagramming the letters.
'at' is a charade indicator (letters next to each other).
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'orgies' with letters rearranged gives 'ogreis'.
'ogreis'+'h'='OGREISH'
(Other definitions for ogreish that I've seen before include "Looking like a fiend" , "Cruel and terrifying" , "Monstrous, misshapen, cruel" , "Fearsome" , "Terrifyingly big" .)