latency

Etymology

It is formed from English latent + -ency.^[2][3][4][5] The OED compares Medieval Latin latentia (“concealment”), recorded in British sources from the 13th century.^[2] The adjective latent is from Latin latēns (“lying hidden”), the present participle of lateō (“to lie hidden”),^[4][3] which Watkins traces to Proto-Indo-European *lādh- (“to be hidden”).^[4]

Earliest recorded meaning

The state of being concealed or latent: 1615, in Thomas Worthington's Whyte dyed Black.^[2][5] Etymonline dates it to the 1630s,^[4] and Dictionary.com to 1630–40.^[6]

Semantic evolution

From the general sense of hidden existence, medicine took the word in 1661 for the latent state of a disease or infection.^[2] In physiology and psychology it was applied from 1865 to the interval between a stimulus and the response, especially in muscle,^[2][3] which Etymonline dates to 1882 and connects with the idea of dormancy.^[4] In 1910 the translation of Freud by A. A. Brill gave it the psychoanalytic sense of the period from about five to puberty in which sexual feelings are repressed or sublimated.^[2][3] In computing it named, from 1947, the delay before a transfer of data begins,^[2][3] Etymonline dating latency time to 1954.^[4]

Timeline

• 1615 – the condition of being latent; concealed existence.^[2][5] Etymonline dates the word to the 1630s.^[4]
• 1661 – in medicine, the latent state of a disease or infection.^[2]
• 1865 – the interval between a stimulus and the response.^[2] Etymonline dates this sense to 1882.^[4]
• 1910 – in psychoanalysis, the period of sexual latency in childhood.^[2][3]
• 1947 – in computing, the delay before a data transfer begins.^[2][3] Etymonline dates latency time to 1954.^[4]

Meanings

Noun

1. The state of being latent; a dormant condition.^[5][2]
2. Something that is latent: the latencies of the plan.^[5]
3. The delay between a stimulus and the response to it; a latent period.^[5][2][3]
4. (medicine) The state of a disease or virus present in the body without producing symptoms.^[5][2]
5. (psychoanalysis) The stage of childhood, from about five to puberty, in which sexual feelings are held to be repressed.^[2][3]
6. (computing) The delay before a transfer of data begins, or the time data takes to travel across a network.^[2][3]

Related words

• latent
• lethargy

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 p q Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i j Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b c d e f g h i Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House