Shoves the tom cat outside (6)
I believe the answer is:
pushes
'shoves' is the definition.
(I've seen this in another clue)
'tom cat outside' is the wordplay.
'tom' becomes 'he' (I can't explain this - if you can you should give a lot more credence to this answer).
'cat' becomes 'puss' (puss is a kind of cat).
'outside' means one lot of letters goes inside another (some letters go outside others).
'he' inserted into 'puss' is 'PUSHES'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for pushes that I've seen before include "Presses, drives, or impels to action" , "Propels" , "Presses to move" , "Shoves" .)