Put your foot in the WPB (4)
I believe the answer is:
step
'put' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'your foot in the wpb' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
The remaining letters 'sep' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for step that I've seen before include "Stair" , "Second half of quick 20?" , "Put foot on a pest" , "Place foot on as with a pest" , "Section of flight" .)