Tusk :: Tusk (n.) One of the elongated incisor or canine teeth of the wild boar, elephant, etc.; hence, any long, protruding tooth..
Tusk :: Tusk (n.) A toothshell, or Dentalium; -- called also tusk-shell..
Tusk :: Tusk (n.) A projecting member like a tenon, and serving the same or a similar purpose, but composed of several steps, or offsets. Thus, in the illustration, a is the tusk, and each of the several parts, or offsets, is called a tooth..