Eventually finish parody, scratching head (3,2)
I believe the answer is:
end up
'eventually finish' is the definition.
(how things end up is how they finish)
'parody scratching head' is the wordplay.
'parody' becomes 'send up' (synonyms).
'scratching head' means to remove the first letter (the word's head is removed).
'sendup' with its initial letter taken away is 'END UP'.
(Other definitions for end up that I've seen before include "Eventually become" , "inverted" , "finally arrive" , "on your head, maybe" , "Ultimately become" .)