Peg turns bawdy, smothering Oscar (5)
I believe the answer is:
dowel
'peg' is the definition.
(a dowel is a wooden peg)
'turns bawdy smothering oscar' is the wordplay.
'turns' says the letters should be written in reverse.
'bawdy' becomes 'lewd' (I've seen this in another clue).
'smothering' means one lot of letters goes inside another.
'oscar' becomes 'O' (phonetic alphabet: alpha, bravo, charlie etc.).
'lewd' placed around 'o' is 'lewod'.
'lewod' backwards is 'DOWEL'.
(Other definitions for dowel that I've seen before include "Cylindrical fastening pin" , "Peg for joining wood" , "Fixing peg" , "Fastening peg for joint" , "Pin that holds two pieces of wood together" .)