Page item, tiny piece (8)
I believe the answer is:
particle
'tiny piece' is the definition.
(I've seen this before)
'page item' is the wordplay.
'page' becomes 'p'.
'item' becomes 'article' (I've seen this before).
'p'+'article'='PARTICLE'
(Other definitions for particle that I've seen before include "Eg, a proton" , "Minute fragment" , "Minute portion" , "Small unit of matter" , "Molecule" .)