partner
n.
c.1300, altered from parcener (late 13c.), from Old French parçonier "partner, associate; joint owner, joint heir," from parçon "partition, division. portion, share, lot," from Latin partitionem (nominative partitio) "a sharing, partition, division, distribution" (see partition, n.). Form in English influenced by part (n.). The word also may represent Old French part tenour "part holder."
v.
1610s, transitive, "to make a partner," from partner, n.. Intransitive sense from 1961. Related: Partnered; partnering.
〔李〕[part=part部分；-ner (-er) n.=person人→“person who shares a part with other(s)与他人分担部分者”→] n.① one who is associated with another 同伙，搭档