hardtack

• hard tack

hard +‎ tack

This etymology is incomplete. You can help Wiktionary by elaborating on the origins of this term.

hardtack (countable and uncountable, plural hardtacks)

1. (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)

   • 1913, Joseph C[rosby] Lincoln, chapter VIII, in Mr. Pratt’s Patients, New York, N.Y., London: D[aniel] Appleton and Company, →OCLC:

     Philander went into the next room […] and came back with a salt mackerel that dripped brine like a rainstorm. Then he put the coffee pot on the stove and rummaged out a loaf of dry bread and some hardtack.

   • 1989, Aleksandr Solzhenitsyn, translated by H. T. Willetts, August 1914, Farrar, Straus and Giroux, →ISBN, page 71:

     Bread and fodder had to be brought up over longer and longer distances, it was more difficult all the time, transport was lacking, the army had already eaten two-thirds of its hardtack, exhausted men were marching in baking heat along sandy roads into emptiness!

• (hard biscuit): pilot biscuit, pilot bread, sea biscuit, sea bread, ship's biscuit, ship bread, ship biscuit

• reefer's nut
• soft tack