Uncle, say, accepting, say, demotion (10)
I believe the answer is:
relegation
'demotion' is the definition.
(I've seen this before)
'uncle say accepting say' is the wordplay.
'uncle say' becomes 'relation' (uncle is a kind of relation).
'accepting' means one lot of letters goes inside another (inserted letters are accepted).
'say' becomes 'eg' (both can mean for example).
'relation' placed around 'eg' is 'RELEGATION'.
(Other definitions for relegation that I've seen before include "that's going down" , "Demotion, to a lower league" , "Transference to a lower league" , "Lowering of status" .)