Adjustment puts wife in wood (5)
I believe the answer is:
tweak
'adjustment' is the definition.
(I have seen 'Fine adjustment ' mean 'tweak' so perhaps 'adjustment' could also mean 'tweak')
'wife in wood' is the wordplay.
'wife' becomes 'w' (abbreviation).
'in' means one lot of letters goes inside another.
'wood' becomes 'teak' (type of timber).
'w' put within 'teak' is 'TWEAK'.
'puts' is the link.
(Other definitions for tweak that I've seen before include "Make minor adjustment" , "Change slightly" , "Twist; adjust finely" , "Twitch" , "spin, thus?" .)