Partner, n.
Etymology: [For parcener, influenced by part.]
1. One who has a part in anything with an other; a partaker; an associate; a sharer. "Partner of his fortune." Shak. Hence: (a) A husband or a wife. (b) Either one of a couple who dance together. (c) One who shares as a member of a partnership in the management, or in the gains and losses, of a business. My other self, the partner of my life. Milton.
2. (Law)
An associate in any business or occupation; a member of a partnership. See Partnership.
3. pl. (Naut.)
2 more senses
A framework of heavy timber surrounding an opening in a deck, to strengthen it for the support of a mast, pump, capstan, or the like. Dormant, or Silent, partner. See under Dormant, a.
Syn. -- Associate; colleague; coadjutor; confederate; partaker; participator; companion; comrade; mate.
1 other Webster entry under this spelling
Partner, v. t.
To associate, to join. [Obs.] Shak.
Shades of meaning
Fernald has no entry of its own for partner; he lists it under accessory, associate.
Where he writes about it:
Partner has come to denote almost exclusively a business connection. — from accessory