From Latin 'duo' (two) + 'plicare' (to fold) — folding something in two to produce a matching pair.
To make an exact copy of something; an identical copy; exactly like something else.
From Latin "duplicātus," past participle of "duplicāre" (to double), from "duplex" (twofold), itself a compound of "duo" (two, from PIE *dwóh₁, two) + "plicāre" (to fold, from PIE *pleḱ-, to plait, to fold). The compound literally means "two-fold." The PIE root *dwóh₁ is one of the most stable reconstructions in comparative linguistics, producing English "two," German "zwei," Greek "δύο" (dýo), Sanskrit "dvā," Russian "dva," and Lithuanian "du." The second element
'Duplicity' — meaning deceit or double-dealing — is literally 'two-foldedness,' from the same root as 'duplicate.' A duplicitous person is 'folded in two,' presenting one face while concealing another. The journey from 'making a copy' to 'being treacherous' runs through the idea that having