Tot's feet caught in twisted reins (7)
I believe the answer is:
snifter
'tot's' is the definition.
(thesaurus)
'feet caught in twisted reins' is the wordplay.
'feet' becomes 'ft' (I've seen this in other clues).
'caught in' means one lot of letters goes inside another.
'twisted' says the letters should be written backwards.
'reins' backwards is 'snier'.
'ft' going within 'snier' is 'SNIFTER'.
(Other definitions for snifter that I've seen before include "14 [NIP]" , "shot" , "Small quantity of alcoholic drink" , "Small alcoholic drink (colloq.)" , "Catcall" .)