Secretly allow (something immoral, illegal, or harmful) to occur.
Conspire to do something immoral, illegal, or harmful.
Early 17th century: from French conniver or Latin connivere ‘shut the eyes (to)’, from con- ‘together’ + an unrecorded word related to nictare ‘to wink’.
Blow a current of air through (grain) in order to remove the chaff./ Manually remove chaff from grain.
Remove (people or things) from a group until only the best ones are left./ Find the useful part of something.
Old English windwian, from wind (see wind).