Type of hound a devotee keeps in Grand Hotel (6)
I believe the answer is:
afghan
'type of hound' is the definition.
(Afghan hound is a breed of dog)
'a devotee keeps in grand hotel' is the wordplay.
'devotee' becomes 'fan' (synonyms).
'keeps in' is an insertion indicator.
'grand' becomes 'G' (G is short for ground as in a thousand).
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'g'+'h'='gh'
'fan' placed around 'gh' is 'fghan'.
'a'+'fghan'='AFGHAN'
(Other definitions for afghan that I've seen before include "Type of hunting dog" , "One from Kabul, perhaps" , "Type of hound" , "A woolly coat" , "Type of coat made from sheepskin" .)