Fit a new tap (3)
I believe the answer is:
apt
'fit' is the definition.
(apt means appropriate or fitting)
'a new tap' is the wordplay.
'a new' indicates anagramming the letters.
'tap' with letters rearranged gives 'APT'.
(Other definitions for apt that I've seen before include "Appropriate for Pat" , "To the point" , "Fit, suitable" , "flat" , "Suitable for Pat" .)