Squash pest on part of staircase (4)
I believe the answer is:
step
'staircase' is the definition.
(thesaurus)
'squash pest on part' is the wordplay.
'squash pest' becomes 'sp' (this might be a standard abbreviation I've not previously seen).
'on' indicates putting letters inside (as in clothing \'on\' a person).
'part' becomes 'te' (te is a kind of part).
'sp' enclosing 'te' is 'STEP'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for step that I've seen before include "Dance move" , "Put foot on a pest" , "Gradation" , "Pace (taken one at a time?)" , "Move a little way" .)