acronym of (de|Fliegerabwehrkanone|Fliegerabwehrkanone). First attested 1938 as “antiaircraft gun”, 1940 as “antiaircraft fire”. Sense of “adverse criticism” attested since 1963 in American English.
1964, David John Cawdell Irving, The Destruction of Dresden, page 74,
[…] to consider whether the city was in February 1945 an undefended city within the meaning of the 1907 Hague Convention, it will be necessary to examine the establishment and subsequent total dispersal of the city's flak batteries, before the date of the triple blow.
2007, Samuel W. Mitcham, Jr., Retreat to the Reich: The German Defeat in France, 1944, footnote, page 30,
He was promoted to general of flak artillery on March 1, 1945, and ended the war as the general of the flak arm at OKL, the High Command of the Luftwaffe.
Anti-aircraft shell fire.
1943 November 29, Target: Germany, in Life, page 80,
At 1057 we were just over the islands and at 1100 the tail gunner reported flak at six o'clock, below.
1999, Brian O'Neill, Half a Wing, Three Engines and a Prayer, page 118,
I could hear the fragments from the flak shells hitting the plane like someone throwing rocks at it.
1990, Joel H. Spring, The American School, 1642-1990, page 380,
This filter Herman and Chomsky call “flak,” which refers to letters, speeches, phone calls, and other forms of group and individual complaints. Advertisers and broadcasters avoid programming content that might cause large volumes of flak.
2006, Edward Herman, Noam Chomsky, A Propaganda Model, in 2006 [2001], Meenakshi Gigi Durham, Douglas Kellner (editors), Media and Cultural Studies: Keyworks, revised edition, page 277,
AIM head, Reed Irvine's diatribes are frequently published, and right-wing network flaks who regularly assail the “liberal media,” such as Michael Ledeen, are given Op-ed column space, sympathetic reviews, and a regular place on talk shows as experts.
From (sqj-pro|*awa-laka), from (ine-pro|*lek-) ‘to jump, scuttle’ (compare Norwegian dialect (no|lakka) ‘to hop, patter about’, Latvian (lv|lèkt), Ancient Greek (grc|ληκάω) ‘to dance to music’).[1]
Verbo[redakti]
