Where does “antiflapping” come from?

antiflapping (English) comes from English anti, from English anti-, from Ancient Greek ἀντι-, from Ancient Greek ᾰ̓ντῐ́ — opposite.

Ancestry of “antiflapping”, step by step

antiflapping traces back through two separate lines of ancestry.

via English anti

StepLanguageWordMeaning
1EnglishantiOpposed to something; That has a torsion angle...
2Englishanti-Against, hostile to; Contrasting with the norm;...
3Ancient Greekἀντι-anti-, against; like, reminiscent of
4Ancient Greekᾰ̓ντῐ́opposite

via English flapping

StepLanguageWordMeaning
1Englishflappingthat flaps or flap; An instance where one flaps;...
2EnglishflapAnything broad and flexible that hangs loose, or...
3Middle Englishflap
Every word from Ancient Greek ᾰ̓ντῐ́
antiflapping — Etymology, Origin & Word History | Etymology Explorer