Arranging seats if making celebrations (7)
I believe the answer is:
fiestas
'celebrations' is the definition.
(fiesta is a kind of celebration)
'arranging seats if' is the wordplay.
'arranging' indicates anagramming the letters.
'seats'+'if'='seatsif'
'seatsif' with letters rearranged gives 'FIESTAS'.
'making' acts as a link.
(Other definitions for fiestas that I've seen before include "It's safe to have public celebrations in Spain" , "holidays ..." .)