'partner' originates from Old French, specifically the word 'parçonier,' where 'parçon' meant 'part or share.'

'parçonier' transformed into the Middle English word 'partener,' and eventually became the modern English word 'partner.'

Initially, it meant 'one who shares or divides,' but over time it evolved into its current meaning of 'one who is associated with another in a common activity.'