From The Collaborative International Dictionary of English v.0.48:
Tap \Tap\, v. t. [imp. & p. p. Tapped; p. pr. & vb. n.
Tapping.] [F. taper to strike; of Teutonic origin; cf.
dial. G. tapp, tapps, a blow, tappe a paw, fist, G. tappen to
grope.]
1. To strike with a slight or gentle blow; to touch gently;
to rap lightly; to pat; as, to tap one with the hand or a
cane.
[1913 Webster]
2. To put a new sole or heel on; as, to tap shoes.
[1913 Webster]