HARDTACK
hardtack, pilot biscuit, pilot bread, sea biscuit, ship biscuit
(noun) very hard unsalted biscuit or bread; a former ship’s staple
hardtack
(noun) a mountain mahogany
Source: WordNet® 3.1
Noun
hardtack (countable and uncountable, plural hardtacks)
(nautical) A large, hard biscuit made from unleavened flour and water; formerly used as a long-term staple food aboard ships.
Synonyms: Anzac wafer, sheet iron, tooth duller, worm castle (all military slang)
Synonyms
• (hard biscuit): pilot biscuit, pilot bread, sea biscuit, sea bread, ship's biscuit, ship biscuit
Source: Wiktionary
Hard"-tack`, n.
Definition: A name given by soldiers and sailors to a kind of hard biscuit
or sea bread.
Source: Webster’s Unabridged Dictionary 1913 Edition