Writer sensed end (4,3)
I believe the answer is:
felt tip
'writer' is the definition.
(a felt tip pen is something which writes)
'sensed end' is the wordplay.
'sensed' becomes 'felt' ('feel' can be a synonym of 'sense').
'end' becomes 'tip' (tip is a kind of end).
'felt'+'tip'='FELT-TIP'
(Other definitions for felt tip that I've seen before include "writer" , "Type of pen" , "Variety of pen" , "(Pen with) fibre point" .)