Etching \Etch"ing\, n.

1. The act, art, or practice of engraving by means of acid which eats away lines or surfaces left unprotected in metal, glass, or the like. See Etch, v. t.

2. A design carried out by means of the above process; a pattern on metal, glass, etc., produced by etching.

3. An impression on paper, parchment, or other material, taken in ink from an etched plate.

Etching figures (Min.), markings produced on the face of a crystal by the action of an appropriate solvent. They have usually a definite form, and are important as revealing the molecular structure.

Etching needle, a sharp-pointed steel instrument with which lines are drawn in the ground or varnish in etching.

Etching stitch (Needlework), a stitch used outline embroidery.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Etch \Etch\, v. t. [imp. & p. p. Etched; p. pr. & vb. n. Etching.]

[D. etsen, G. ["a]tzen to feed, corrode, etch. MHG. etzen, causative of ezzen to eat, G. essen ??. See Eat.]

1. To produce, as figures or designs, on mental, glass, or the like, by means of lines or strokes eaten in or corroded by means of some strong acid.

Note: The plate is first covered with varnish, or some other ground capable of resisting the acid, and this is then scored or scratched with a needle, or similar instrument, so as to form the drawing; the plate is then covered with acid, which corrodes the metal in the lines thus laid bare.

2. To subject to etching; to draw upon and bite with acid, as a plate of metal.

I was etching a plate at the beginning of 1875. --Hamerton.

3. To sketch; to delineate. [R.]

There are many empty terms to be found in some learned writes, to which they had recourse to etch out their system. --Locke.

Source: Webster's Revised Unabridged Dictionary (1913)