The story
- German · borrowed fromFlaK
- English todayflak
Borrowed from German FlaK, short for Fliegerabwehrkanone (“anti airplane cannon”).
First known use, by meaning
- from 1938 Ground-based anti-aircraft guns firing explosive shells.
- from 1940 Anti-aircraft shell fire.
- from 1963 Adverse criticism.
Etymology from Wiktionary, CC BY-SA 4.0.