Pierce page with what one is writing with? (4)
I believe the answer is:
pink
'pierce' is the definition.
(thesaurus)
'page with what one is writing with?' is the wordplay.
'page' becomes 'p'.
'with' says to put letters next to each other.
'what one is writing with?' becomes 'ink'.
'p'+'ink'='PINK'
(Other definitions for pink that I've seen before include "Colour; garden plant" , "Salmon-coloured" , "stab" , "Cut wavy edge on, plant" , "Colour; pop singer" .)