What is "scotching"

Scotch \Scotch\, v. t. [imp. & p. p. Scotched; p. pr. & vb. n. Scotching.] [Cf. Prov. E. scote a prop, and Walloon ascot a prop, ascoter to prop, F. accoter, also Armor. skoaz the shoulder, skoazia to shoulder up, to prop, to support, W. ysgwydd a shoulder, ysgwyddo to shoulder. Cf. Scoat.] To shoulder up; to prop or block with a wedge, chock, etc., as a wheel, to prevent its rolling or slipping.

Scotching \Scotch"ing\, n. (Masonry) Dressing stone with a pick or pointed instrument.

vb. (present participle of scotch English)