Bait Mike put on end of line, twisting (4)
I believe the answer is:
worm
'bait' is the definition.
(bait when fishing)
'mike put on end of line twisting' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'put on end of' means one lot of letters go next to another (some letters go after others).
'line' becomes 'row' (a row or line of things).
'twisting' shows that the letters should be reversed in order (letters twist back).
'row' in reverse letter order is 'wor'.
'm' after 'wor' is 'WORM'.
(Other definitions for worm that I've seen before include "Reproductive computer virus" , "Pink, slimy subterranean wriggler" , "Wriggly creature" , "Wretched person" , "one leaving cast" .)