What is "to lose the fang"

Fang \Fang\, n. [From Fang, v. t.; cf. AS. fang a taking, booty, G. fang.]

1. (Zo["o]l.) The tusk of an animal, by which the prey is seized and held or torn; a long pointed tooth; esp., one of the usually erectile, venomous teeth of serpents. Also, one of the falcers of a spider.

   Since I am a dog, beware my fangs.
   --Shak.

2. Any shoot or other thing by which hold is taken.

   The protuberant fangs of the yucca.
   --Evelyn.

3. (Anat.) The root, or one of the branches of the root, of a tooth. See Tooth.

4. (Mining) A niche in the side of an adit or shaft, for an air course.
   --Knight.

5. (Mech.) A projecting tooth or prong, as in a part of a lock, or the plate of a belt clamp, or the end of a tool, as a chisel, where it enters the handle.

6. (Naut.)

   1. The valve of a pump box.

   2. A bend or loop of a rope.

      In a fang, fast entangled.

      To lose the fang, said of a pump when the water has gone out; hence:

      To fang a pump, to supply it with the water necessary to make it operate. [Scot.]