Point at Lord Hall gatecrashing celebrity finale (7)
I believe the answer is:
endgame
'finale' is the definition.
'point at lord hall gatecrashing celebrity' is the wordplay.
'point' becomes 'e' (E is an example).
'at' is a charade indicator (letters next to each other).
'lord hall' becomes 'dg' (Tony Hall is DG or director general of the BBC).
'gatecrashing' indicates putting letters inside.
'celebrity' becomes 'name' (I've seen this before).
'dg' put inside 'name' is 'ndgame'.
'e'+'ndgame'='ENDGAME'
(Other definitions for endgame that I've seen before include "moves before mating" , "Final stage in a contest" , "Beckett play" , "contest's final stage" , "Denouement (chess)" .)