Knack \Knack\, v. i. [Prob. of imitative origin; cf. G. knacken to break, Dan. knage to crack, and E. knock.]

1. To crack; to make a sharp, abrupt noise to chink. [Obs. or Prov. Eng.]

--Bp. Hall.

2. To speak affectedly. [Prov. Eng.]

--Halliwell.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Knack \Knack\, n.

1. A petty contrivance; a toy; a plaything; a knickknack.

A knack, a toy, a trick, a baby's cap. --Shak.

2. A readiness in performance; aptness at doing something; skill; facility; dexterity.

The fellow . . . has not the knack with his shears. --B. Jonson.

The dean was famous in his time, And had a kind of knack at rhyme. --Swift.

3. Something performed, or to be done, requiring aptness and dexterity; a trick; a device. ``The knacks of japers.'' --Chaucer.

For how should equal colors do the knack ! --Pope.

Source: Webster's Revised Unabridged Dictionary (1913)