Celebrity is generous welcoming cheers (7)
I believe the answer is:
notable
'celebrity' is the definition.
(I know that notable is a type of celebrity)
'generous welcoming cheers' is the wordplay.
'generous' becomes 'noble'.
'welcoming' indicates putting letters inside (in sense of 'inviting in').
'cheers' becomes 'ta' (both can informally mean thank you).
'noble' enclosing 'ta' is 'NOTABLE'.
'is' acts as a link.
(Other definitions for notable that I've seen before include "well known" , "Eminent" , "Worthy of remark" , "Outstanding" , "VIP" .)