Turn and nod wildly as you get something free (4)
I believe the answer is:
undo
'free' is the definition.
(as in undoing someone's chains)
'turn and nod wildly' is the wordplay.
'turn' becomes 'u' (a 'U-turn' is a kind of turn).
'and' means one lot of letters go next to another.
'wildly' indicates anagramming the letters.
'nod' is an anagram of 'ndo'.
'u'+'ndo'='UNDO'
'as you get something' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for undo that I've seen before include "Release fastening" , "Unfasten - destroy" , "Bring to ruin" , "Open or unfasten" , "Cancel or reverse an action" .)