Christmassy present in the Seychelles (5)
I believe the answer is:
snowy
'christmassy' is the definition.
(Christmas is associated with snow)
'present in the seychelles' is the wordplay.
'present' becomes 'now' (both can mean the current period).
'in' means one lot of letters goes inside another.
'the seychelles' becomes 'SY' (international car registration for the Seychelles).
'now' going inside 'sy' is 'SNOWY'.
(Other definitions for snowy that I've seen before include "Tintin's (white?) dog" , "Tintin's dog - describing winter weather" , "Covered in flakes" , "- Mountains; - owl" , "Wintry" .)