n. [ from the name of the inventor. ] a pen with small metal ball as point of transfer of ink to paper; same as ballpoint pen. Syn. -- ballpoint, ballpoint pen, ballpen. [ WordNet 1.5 ]
{ } a. [ Pref. bi- + rostrate. ] Having a double beak, or two processes resembling beaks. [ 1913 Webster ]
The capsule is bilocular and birostrated. Ed. Encyc. [ 1913 Webster ]