Below, in poesy (5)
I believe the answer is:
neath
'below in poesy' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for neath that I've seen before include "Lower than - a town in West Glamorgan" , "River" , "Town near Swansea" , "Town NE of Swansea" , "Welsh rugby club" .)