Tread on some character's toe (4)
I believe the answer is:
step
'tread' is the definition.
(I know that tread can be written as step)
'on some character's toe' is the wordplay.
'on' says to put letters next to each other.
'some character' becomes 'p'.
'toe' becomes 'ste' (I can't justify this - if you can you should give a lot more credence to this answer).
'p' put after 'ste' is 'STEP'.
Can you help me to learn more?
(Other definitions for step that I've seen before include "Action of the leg" , "Dance move" , "Pace (taken one at a time?)" , "Abrupt change; pace" , "Football" .)