Line you are splitting to once again do hand-outs (10)
I believe the answer is:
literature
'hand-outs' is the definition.
'line you are splitting to once again do' is the wordplay.
'line' becomes 'l'.
'you are' becomes 'ur' (text or internet abbreviation).
'splitting' is an insertion indicator.
'to once again do' becomes 'iterate'.
'ur' inserted into 'iterate' is 'iterature'.
'l'+'iterature'='LITERATURE'
(Other definitions for literature that I've seen before include "Work by Spenser for instance" , "Written material" , "writer's work" , "Written texts" , "Written works of artistic merit" .)