Person who's been ostracised, dismissed by all the players (7)
I believe the answer is:
outcast
'person who's been ostracised' is the definition.
(someone cast out from society)
'dismissed by all the players' is the wordplay.
'dismissed by' suggests deleting specific letters.
'all' becomes 'tout' (I've seen this before).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'players' becomes 'cast' (group of actors).
'tout' with 't' taken out is 'out'.
'out'+'cast'='OUTCAST'
(Other definitions for outcast that I've seen before include "vagabond" , "Displaced person" , "Pariah, society reject" , "Person rejected by a group or society" , "Role of Ishmael" .)