Mostly Messi is accommodated — it's what we do with celebrities (7)
I believe the answer is:
lionise
'it's what we do with celebrities' is the definition.
(lionise means to worship or honour)
'mostly messi is accommodated' is the wordplay.
'mostly' means to remove the last letter.
'messi' becomes 'Lionel' (footballer Lionel Messi).
'accommodated' is an insertion indicator.
'lionel' with its last letter removed is 'lione'.
'lione' enclosing 'is' is 'LIONISE'.
(Other definitions for lionise that I've seen before include "honour" , "Treat as celebrity - like Leo?" , "'Celebrate, treat as a hero (7)'" , "Make fuss of (celebrity)" , "Glorify; treat as a hero" .)