hardtack vs ship biscuit

hardtack and ship biscuit both are nouns.

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

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

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

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

hardtack (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
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