Duplicate
late Middle English (in the sense ‘having two corresponding parts’): from Latin duplicat- ‘doubled’, from the verb duplicare, from duplic- ‘twofold’ (see duplex).
wiktionary
Borrowed from Latin duplicātus, perfect passive participle of duplicō.
etymonline
duplicate (adj.)
early 15c., "having two parts, double," from Latin duplicatus, past participle of duplicare "to double," from duo "two" (from PIE root *dwo- "two") + plicare "to fold" (from PIE root *plek- "to plait"). Meaning "exactly corresponding, that is an exact copy of" is from 1812.
duplicate (v.)
late 15c., "to repeat, produce a second (like the first);" 1620s, "to double," from Latin duplicatus, past participle of duplicare "to double," from duo "two" (from PIE root *dwo- "two") + plicare "to fold" (from PIE root *plek- "to plait"). Related: Duplicated; duplicating.
duplicate (n.)
1530s, "one of two or more things corresponding in every respect to each other," from duplicate (adj.). From 1701 as "another corresponding to a first or original, an exact counterpart or double of an original."
