Swedish inventor’s book appearing in festive season (5)
I believe the answer is:
nobel
'swedish inventor's' is the definition.
(I've seen this before)
'book appearing in festive season' is the wordplay.
'book' becomes 'b' (abbreviation for book).
'appearing in' is an insertion indicator.
'festive season' becomes 'noel' (I've seen this before).
'b' going into 'noel' is 'NOBEL'.
(Other definitions for nobel that I've seen before include "Swedish prize" , "he provided prizes" , "Dynamite inventor, Prize founder" , "Giver of many prizes" , "Prize-endowing Swedish chemist" .)