Christmastime vs season

Christmastime and season both are nouns.

Word	Noun	Adjective	Verb	Adverb
Christmastime	Yes	No	No	No
season	Yes	No	Yes	No

As nouns, season is a hypernym of Christmastime; that is, season is a word with a broader meaning than Christmastime:

Christmastime (noun)	season (noun)
period extending from Dec. 24 to Jan. 6	one of the natural periods into which the year is divided by the equinoxes and solstices or atmospheric conditions
	a recurrent time marked by major holidays
	a period of the year marked by special events or activities in some field

Christmastime (verb)	season (verb)
	make healthy
	make more temperate, acceptable, or suitable by adding something else
	lend flavor to