noun.
A hard biscuit or bread made with only flour and water.
The Century Dictionary and Cyclopedia
noun.
Large, coarse, hard biscuit baked without salt and kiln-dried, much used by sailors and soldiers: ship-biscuit.
noun.
Same as hardhead, 6.
the GNU version of the Collaborative International Dictionary of English
noun.
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
noun.
Any of several mahogany trees, esp. the Cercocarpus betuloides.