Famous chemist releasing book for Christmas (4)
I believe the answer is:
noel
'christmas' is the definition.
(Noel can mean Christmas)
'famous chemist releasing book' is the wordplay.
'famous chemist' becomes 'Nobel' (Alfred Nobel, 1833-1896).
'releasing' suggests deleting specific letters.
'book' becomes 'b' (abbreviation for book).
'nobel' with 'b' taken away is 'NOEL'.
'for' acts as a link.
(Other definitions for noel that I've seen before include "Coward - Christmas" , "Christmas carol" , "Lone male name" , "Christmastime" , "seasonal festival" .)