List origin of hotel fish (4)
I believe the answer is:
heel
'list' is the definition.
(thesaurus)
'origin of hotel fish' is the wordplay.
'origin of' says to take the initial letters.
'fish' becomes 'eel' (eel is a kind of fish**).
The initial letter of 'hotel' is 'h'.
'h'+'eel'='HEEL'
(Other definitions for heel that I've seen before include "secure ball" , "Shoe part - come here, Fido!" , "Achilles' weak spot" , "Reprehensible person" , "Keel over" .)