temper vs good temper

temper and good temper both are nouns.

Word	Noun	Adjective	Verb	Adverb
temper	Yes	No	Yes	No
good temper	Yes	No	No	No

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

temper: a characteristic (habitual or relatively temporary) state of feeling
good temper: a cheerful and agreeable mood

Other hyponyms of temper include peeve, sulk, sulkiness, amiability, good humor, good humour, distemper, ill humor, ill humour.

temper (noun)	good temper (noun)
the elasticity and hardness of a metal object; its ability to absorb considerable energy before cracking	a cheerful and agreeable mood
a disposition to exhibit uncontrolled anger
a characteristic (habitual or relatively temporary) state of feeling
a sudden outburst of anger

temper (verb)	good temper (verb)
make more temperate, acceptable, or suitable by adding something else
adjust the pitch (of pianos)
harden by reheating and cooling in oil
change by restraining or moderating
bring to a desired consistency, texture, or hardness by a process of gradually heating and cooling