\Knack"er\, n.
1. One who makes knickknacks, toys, etc. --Mortimer.
2. One of two or more pieces of bone or wood held loosely
   between the fingers, and struck together by moving the
   hand; -- called also {clapper}. --Halliwell.

\Knack"er\, n. [Cf. Icel. hnakkr a saddle.]
1. a harness maker. [Obs. or Prov. Eng.] --Halliwell.
2. One who slaughters worn-out horses and sells their flesh
   for dog's meat. [Eng.]