Clever Huw's top in Welsh Town (5)
I believe the answer is:
neath
'welsh town' is the definition.
(I've seen this before)
'clever huw's top' is the wordplay.
'clever' becomes 'neat' (I've seen this before).
'top' says to take the initial letters.
The first letter of 'huw' is 'h'.
'neat'+'h'='NEATH'
'in' acts as a link.
(Other definitions for neath that I've seen before include "town in South Wales" , "Welsh industrial town" , "Under, poetically" , "Town NE of Swansea" , "Under (poetic)" .)