Notice archdeacon on time for run-up to Christmas (6)
I believe the answer is:
advent
'run-up to christmas' is the definition.
(I've seen this before)
'notice archdeacon on time' is the wordplay.
'notice' becomes 'ad'.
'archdeacon' becomes 'ven'.
'on' says to put letters next to each other.
'time' becomes 't'.
'ad'+'ven'+'t'='ADVENT'
'for' is the link.
(Other definitions for advent that I've seen before include "Second Coming" , "Season preceding Christmas" , "Christmas shopping time in" , "Period before Christmas" , "Time approaching Christmas" .)