shingle vs signboard

shingle and signboard both are nouns.

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

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

shingle: a small signboard outside the office of a lawyer or doctor, e.g.
signboard: structure displaying a board on which advertisements can be posted

Other hypernyms of shingle include sign.

shingle (noun)	signboard (noun)
a small signboard outside the office of a lawyer or doctor, e.g.	structure displaying a board on which advertisements can be posted
building material used as siding or roofing
coarse beach gravel of small waterworn stones and pebbles (or a stretch of shore covered with such gravel)

shingle (verb)	signboard (verb)
cover with shingles