Hoteliers lost straying cat (13)
I believe the answer is:
tortoiseshell
'cat' is the definition.
(tortoiseshell is a kind of cat)
'hoteliers lost straying' is the wordplay.
'straying' indicates anagramming the letters.
'hoteliers'+'lost'='hotelierslost'
'hotelierslost' with letters rearranged gives 'TORTOISESHELL'.
(Other definitions for tortoiseshell that I've seen before include "The case of the slow-moving" , "Mottled plated ornamental substance" , "Butterfly - yellow-brown mottled material" , "Butterfly - cat" , "Ornamental material" .)