scoreboard vs signboard

scoreboard and signboard both are nouns.

Word	Noun	Adjective	Verb	Adverb
scoreboard	Yes	No	No	No
signboard	Yes	No	No	No

As nouns, signboard is a hypernym of scoreboard; that is, signboard is a word with a broader meaning than scoreboard:

scoreboard: a large board for displaying the score of a contest (and some other information)
signboard: structure displaying a board on which advertisements can be posted

Other hypernyms of scoreboard include board, sign.

scoreboard (noun)	signboard (noun)
a large board for displaying the score of a contest (and some other information)	structure displaying a board on which advertisements can be posted