\Harts"horn`\, n.
1. The horn or antler of the hart, or male red deer.

2. Spirits of hartshorn (see below); volatile salts.

{Hartshorn plantain} (Bot.), an annual species of plantain
   ({Plantago Coronopus}); -- called also {duck's-horn}.
   --Booth.

{Hartshorn shavings}, originally taken from the horns of
   harts, are now obtained chiefly by planing down the bones
   of calves. They afford a kind of jelly. --Hebert.

{Salt of hartshorn} (Chem.), an impure solid carbonate of
   ammonia, obtained by the destructive distillation of
   hartshorn, or any kind of bone; volatile salts. --Brande &
   C.

{Spirits of hartshorn} (Chem.), a solution of ammonia in
   water; -- so called because formerly obtained from
   hartshorn shavings by destructive distillation. Similar
   ammoniacal solutions from other sources have received the
   same name.