sea biscuit vs pilot biscuit

sea biscuit and pilot biscuit both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea biscuit	Yes	No	No	No
pilot biscuit	Yes	No	No	No

As nouns, sea biscuit and pilot biscuit are synonyms defined as:

sea biscuit and pilot biscuit: very hard unsalted biscuit or bread; a former ship's staple

Other synonyms of sea biscuit include hardtack, pilot bread, ship biscuit.

sea biscuit (noun)	pilot biscuit (noun)
very hard unsalted biscuit or bread; a former ship's staple	very hard unsalted biscuit or bread; a former ship's staple