Meanings
nounthree-letter agency (plural three-letter agencies)
plural three-letter agencies · alternative three letter agency
- UShumorousAny intelligence agency of the United States federal government.
- USbroadlyhumorousAny intelligence agency, regardless of nationality or allegiance.
Origin
From the initialisms of major intelligence agencies in the United States, such as the CIA, FBI and NSA.
Full word history & related roots →Cite this entry
APA
three-letter agency. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/three-letter%20agency
MLA
“three-letter agency.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/three-letter%20agency. Accessed November 5, 2026.
Chicago
WatkinsX Dictionary, s.v. “three-letter agency,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/three-letter%20agency.
Source: three-letter agency on Wiktionary, CC BY-SA 4.0.