I must leave Tobias turning a wooden shoe (5)
I believe the answer is:
sabot
'a wooden shoe' is the definition.
(I've seen this before)
'i must leave tobias turning' is the wordplay.
'must leave' indicates named letters should be taken away.
'turning' says the letters should be written in reverse.
'tobias' with 'i' taken away is 'tobas'.
'tobas' reversed gives 'SABOT'.
(Other definitions for sabot that I've seen before include "French clog" , "Simple shoe" , "Boast about wooden shoe" , "sole support?" , "French wooden shoe" .)