detector

Etymology

It is borrowed from Late Latin dētēctor (“revealer, uncoverer”),^[2][3][4][5] an agent noun from dētegō (“to uncover, expose, reveal”),^[2][3][4] from dē- (“un-, off”) and tegō (“to cover”),^[6][3] from Proto-Indo-European *(s)teg- (“to cover”).^[6][3] The OED notes that the Latin noun is found in Tertullian.^[2] The Shorter Oxford takes it instead as formed in English from detect and -or.^[7]

Earliest recorded meaning

A person or thing that discloses or reveals something; an informer or accuser: 1541, in Paynell's translation of the Conspiracy of Catiline.^[2][3] This sense was obsolete by the mid 18th century.^[2][7]

Semantic evolution

From 1608, in Shakespeare's King Lear, a detector was a person who finds out what is hidden or tends to escape notice.^[2][7] The word moved to devices in the 19th century, following the senses of detect: first, in 1833, an arrangement in a lock that showed and frustrated any attempt to tamper with it,^[2][3] then a portable galvanometer for testing electric current (1860), any device that detects something (1894) and, in early wireless telegraphy, a rectifier for high-frequency signals (1895).^[2] In the United States a bank-note detector was a published list of current notes with their real value (1893).^[2]

Timeline

• 1541 – a revealer, informer or accuser (obsolete by 1742).^[2]
• 1608 – one who finds out what is concealed.^[2]
• 1833 – a device in a lock showing any attempt at tampering.^[2][3]
• 1860 – a portable galvanometer for testing current.^[2]
• 1894 – any device or circuit for detecting something.^[2]
• 1895 – a rectifier used in wireless telegraphy.^[2]

Modern meaning

Noun

1. A device that senses the presence of something, such as smoke, metal or radiation, and gives a signal: The detector beeped as soon as he lit the candle.
2. (electronics) A device or circuit that extracts the information from a radio signal; a demodulator.
3. A person or thing that detects something.

Word family

• microdetector
• photodetector
• lie detector
• smoke detector
• metal detector

Related words

• detect
• detection
• detective
• protect
• thatch

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
5. ^ Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press