Make some mousetraps ready (3)
I believe the answer is:
set
'make' is the definition.
(setting is a kind of making)
'some mousetraps ready' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'SET' can be found hidden inside 'mousetraps ready'.
(Other definitions for set that I've seen before include "See 16 Down" , "Determined or congealed" , "Cake < , plonk < , something served" , "Fix in place; similar group" , "several games" .)