A measure of pest control? (4)
I believe the answer is:
step
'a measure' is the definition.
('step' can be a synonym of 'measure')
'pest control?' is the wordplay.
'control?' indicates anagramming the letters (I've seen 'control' mean this).
'pest' with letters rearranged gives 'STEP'.
'of' is the link.
(Other definitions for step that I've seen before include "Ladder rung; pace" , "Measure taken" , "Tramp" , "short distance" , "'Stage, rung (4)'" .)