duplicate
adj.
mid-15c., "having two parts, double," from Latin duplicatus, past participle of duplicare "to double," from duo "two" (see two) + plicare "to fold" see ply, v.1). Meaning "exactly corresponding, that is an exact copy of" is from 1812.
v.
1620s, "to double," from Latin duplicatus, past participle of duplicare (see duplicate, adj.). Meaning "make an exact copy" is from 1640s (implied in duplicated). Related: Duplicating. The noun is first recorded 1530s.
〔李〕[du;plic;-atea.] a.复制的，副的 n.复制品； 副本 ←du,dupl (L duo,duples)=two, twofold 二，两倍
〔蒋〕[du双，二，plic重复，重，-ate使…] 使成双，复制，复写；[-ate…的] 二重的，二倍的，复制的，副的；[转作名词] 复制品
〔蒋〕[du双，二，plic重叠，重复，-ate使…] 使成双，复制，复写;[-ate形容词后缀，…的] 二重的，二倍的，复制的;[转为名词] 复制品