sketch (v.) Look up sketch at Dictionary.com
1690s, "present the essential facts of," from sketch (n.). Meaning "draw, portray in outline and partial shading" is from 1725. Related: Sketched; sketcher; sketching.
sketch (n.) Look up sketch at Dictionary.com
"rough drawing intended to serve as the basis for a finished picture," 1660s, from Dutch schets or Low German skizze, both apparently 17c. artists' borrowings from Italian schizzo "sketch, drawing," which is commonly said to be from Latin *schedius (OED compares schedia "raft," schedium "an extemporaneous poem"), from or related to Greek skhedios "temporary, extemporaneous, done or made off-hand," related to skhema "form, shape, appearance" (see scheme (n.)). But according to Barnhart Italian schizzo is a special use of schizzo "a splash, squirt," from schizzare "to splash or squirt," of uncertain origin.

Extended sense of "brief account" is from 1660s; meaning "short play or performance, usually comic" is from 1789. Sketch-book recorded from 1820. German Skizze, French esquisse, Spanish esquicio are likewise from Italian schizzo.