Geordie entertaining in matches for a decade (8)
I believe the answer is:
nineties
'for a decade' is the definition.
(the nineties is a decade)
'geordie entertaining in matches' is the wordplay.
'geordie' becomes 'NE' (Geordies are from Tyneside in the North East).
'entertaining' is an insertion indicator.
'matches' becomes 'ties' (I've seen this in other clues).
'ne' going around 'in' is 'nine'.
'nine'+'ties'='NINETIES'
(Other definitions for nineties that I've seen before include "possibly last period of life" , "make batsmen nervous" , "Last decade of century" , "Time" , "Recent decade" .)