Unleavened vs. Hardtack — What's the Difference?

Made without yeast or any other leavening agent

Hardtack (or hard tack) is a simple type of dense biscuit or cracker made from flour, water, and sometimes salt. Hardtack is inexpensive and long-lasting.

Without any yeast or other raising agent

A hard biscuit or bread made with only flour and water. Also called sea biscuit, sea bread, ship biscuit.

Not leavened; containing no leaven; as, unleavened bread.

(nautical) A large, hard biscuit made from unleavened flour and water; formerly used as a long-term staple food aboard ships.

Made without leavening;

A name given by soldiers and sailors to a kind of unleavened hard biscuit or sea bread. Called also pilot biscuit, pilot bread, ship biscuit and ship bread

Any of several mahogany trees, esp. the Cercocarpus betuloides.

Very hard unsalted biscuit or bread; a former ship's staple

A mountain mahogany