shorebird vs longlegs

shorebird and longlegs both are nouns.

Word	Noun	Adjective	Verb	Adverb
shorebird	Yes	No	No	No
longlegs	Yes	No	No	No

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

shorebird: any of numerous wading birds that frequent mostly seashores and estuaries
longlegs: long-legged three-toed black-and-white wading bird of inland ponds and marshes or brackish lagoons

shorebird (noun)	longlegs (noun)
any of numerous wading birds that frequent mostly seashores and estuaries	long-legged three-toed black-and-white wading bird of inland ponds and marshes or brackish lagoons