humor vs good humour

humor and good humour both are nouns.

Word	Noun	Adjective	Verb	Adverb
humor	Yes	No	Yes	No
good humour	Yes	No	No	No

As nouns, good humour is a hyponym of humor; that is, good humour is a word with a more specific, narrower meaning than humor:

humor (noun)	good humour (noun)
the quality of being funny	a cheerful and agreeable mood
the trait of appreciating (and being able to express) the humorous
the liquid parts of the body
(Middle Ages) one of the four fluids in the body whose balance was believed to determine your emotional and physical state
a message whose ingenuity or verbal skill or incongruity has the power to evoke laughter
a characteristic (habitual or relatively temporary) state of feeling

humor (verb)	good humour (verb)
put into a good mood