intelligence

Etymology

From Middle English intelligence, from Old French intelligence, from Latin intelligentia, which is from inter- (“between”) + legere (“choose, pick out, read”), or Proto-Italic *legō (“to care”). Doublet of intelligentsia.

noun

1. (chiefly uncountable) Capacity of mind, especially to understand principles, truths, facts or meanings, acquire knowledge, and apply it to practice; the ability to comprehend and learn.
   ...the test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function. 1936 Feb., F. Scott Fitzgerald, "The Crack-Up", Esquire
   Irregular bedtimes may disrupt healthy brain development in young children, according to a study of intelligence and sleeping habits. ¶ Going to bed at a different time each night affected girls more than boys, but both fared worse on mental tasks than children who had a set bedtime, researchers found. 2013-07-19, Ian Sample, “Irregular bedtimes may affect children's brains”, in The Guardian Weekly, volume 189, number 6, page 34
2. (chiefly uncountable) The quality of making use or having made use of such capacities: depth of understanding, mental quickness.
   From a religious point of view, a bodhisattva with sharp faculties and great intelligence can cause a tremendous upheaval if he or she misuses that power under the influence of negative emotions, like attachment and hatred. 2018, Dalai Lama, translated by Dhondup Tsering, Introduction to Buddhism, page 8
3. (countable) An entity that has such capacities.
   The living intelligence, the Martian within the hood, was slain and splashed to the four winds of heaven, and the thing was now but a mere intricate device of metal whirling to destruction. 1898, H.G. Wells, The War of the Worlds, London: William Heinemann, page 102
   But there are latent powers within man alone that are not yet fully understood and … we cannot definitely state what is, and what is not, due to the interference or influence of discarnate intelligences. 1936, Rollo Ahmed, The Black Art, London: Long, page 275
   He passes beyond the projections and thought forms of his own creation to the wholly other and independent world of the angelic intelligences. 1981, William Irwin Thompson, The Time Falling Bodies Take to Light: Mythology, Sexuality and the Origins of Culture, London: Rider/Hutchinson & Co., page 228
4. (chiefly uncountable) Information, often secret, about an enemy or about hostile activities.
   Their lack of good intelligence also meant that they vastly overestimated the size of their foes for far too long, hails of armor-piercing shells doing comparatively little damage compared to the high explosive that they should have been using. 27 February 2019, Drachinifel, 40:01 from the start, in The Battle of Samar - Odds? What are those?, archived from the original on 2022-11-03
5. (countable) A political or military department, agency or unit designed to gather information, usually secret, about the enemy or about hostile activities.
6. (dated) Acquaintance; intercourse; familiarity.