Charge around first thing to celebrate (4)
I believe the answer is:
fete
'celebrate' is the definition.
(synonyms)
'charge around first thing' is the wordplay.
'charge' becomes 'fee' (fee is a kind of charge).
'around' indicates putting letters inside.
'first thing' becomes 't' (1st letter of 'thing').
'fee' placed around 't' is 'FETE'.
'to' acts as a link.
(Other definitions for fete that I've seen before include "Outdoor festival" , "Outdoor entertainment and sale, often for charity" , "Outdoor gala" , "Outdoor entertainment run for charity" , "Elaborate outdoor party" .)