pilot biscuit vs ship biscuit

pilot biscuit and ship biscuit both are nouns.

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

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

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

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

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