late 14c., "mark off verse in metric feet," from Late Latin scandere "to scan verse," originally, in classical Latin, "to climb, rise, mount" (the connecting notion is of the rising and falling rhythm of poetry), from PIE *skand- "to spring, leap, climb" (cf. Sanskrit skandati "hastens, leaps, jumps;" Greek skandalon "stumbling block;" Middle Irish sescaind "he sprang, jumped," sceinm "a bound, jump").
Missing -d in English is probably from confusion with suffix -ed (see lawn (n.1)). Sense of "look at closely, examine minutely (as one does when counting metrical feet in poetry)" first recorded 1540s. The (opposite) sense of "look over quickly, skim" is first attested 1926. Related: Scanned; scanning.
1706, "close investigation," from scan (v.). Meaning "act of scanning" is from 1937; sense of "image obtained by scanning" is from 1953.
v. scanned, scan·ning, scans
To move a finely focused beam of light or electrons in a systematic pattern over a surface in order to reproduce or sense and subsequently transmit an image.
To examine a body or a body part with a CAT scanner or similar scanning apparatus.
To search stored computer data automatically for specific data.
The act or an instance of scanning.
Examination of a body or body part by a CAT scanner or similar scanning apparatus.
A picture or an image that is produced by this means.