hardtack

• hard tack

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.
   • 1913, Joseph C. Lincoln, chapter 8, in Mr. Pratt's Patients:

     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, H. T. Willetts (translator), Aleksandr Solzhenitsyn (author), 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 biscuit

• reefer's nut
• softtack