scanner (Noun) — An electronic device that generates a digital representation of an image for data input to a computer.
scanner (Noun) — Someone who scans verse to determine the number and prosodic value of the syllables.
scanner (Noun) — A radar dish that rotates or oscillates in order to scan a broad area.
scanner (Noun) — A radio receiver that moves automatically across some selected range of frequencies looking for some signal or condition. ex. "they used scanners to monitor police radio channels"