Writer was keenly aware of suggestion (4,3)
I believe the answer is:
felt tip
'writer' is the definition.
(a felt tip pen is something which writes)
'keenly aware of suggestion' is the wordplay.
'keenly aware of' becomes 'felt' (I can't justify this - if you can you should give a lot more credence to this answer).
'suggestion' becomes 'tip' (tip is a kind of suggestion).
'felt'+'tip'='FELT-TIP'
'was' is the link.
Can you help me to learn more?
(Other definitions for felt tip that I've seen before include "Variety of pen" , "Type of pen" , "(Pen with) fibre point" , "writer" .)