detector
UK: dɪˈtektə | US: dɪˈtektər
n. a device or instrument designed to detect, measure, or identify something (e.g., smoke, motion, or radiation).
n. a person or thing that discovers or identifies something.
The word "detector" emerged in the early 16th century, combining the Latin root detect- (to uncover or expose) with the agentive suffix -or. Originally used for people who uncovered truths (e.g., crime detectors), it later expanded to mechanical devices (e.g., metal detectors) as technology advanced. The logic reflects a shift from human action to automated discovery.
The smoke detector alerted the family to the fire.
Scientists developed a new radiation detector for safety checks.
His keen eye acted like a lie detector during the interview.
The motion detector lights activated as she walked by.
This device is a sophisticated gas detector used in mines.