Copartner

• POS: Noun
• HYPHEN: co=part=ner

CIDE DICTIONARY

Copartner, n. 

 One who is jointly concerned with one or more persons in business, etc.; a partner; an associate; a partaker; a sharer.  [1913 Webster]
"the associates and copartners of our loss."  [1913 Webster]

OXFORD DICTIONARY

Copartner, n. a partner or associate, esp. when sharing equally.

Derivative

copartnership n.

ROGET THESAURUS

Copartner

Friend

N friend, friend of one's bosom, alter ego, best friend, bosom friend, soulmate, fast friend, amicus, usque ad aras, fidus Achates, persona grata, acquaintance, neighbor, next-door neighbor, casual acquaintance, nodding acquaintance, wellwisher, favorer, fautor, patron, Mecaenas, tutelary saint, good genius, advocate, partisan, sympathizer, ally, friend in need, comrade, mate, companion, familiar, confrere, comrade, camarade, confidante, intimate, old crony, crony, chum, pal, buddy, bosom buddy, playfellow, playmate, childhood friend, bedfellow, bedmate, chamber fellow, associate, colleague, compeer, schoolmate, schoolfellow, classfellow, classman, classmate, roommate, fellow-man, stable companion, best man, maid of honor, matron of honor, compatriot, fellow countryman, countryman, shopmate, fellow-worker, shipmate, messmate, fellow companion, boon companion, pot companion, copartner, partner, senior partner, junior partner, Arcades ambo Pylades and Orestes Castor and Pollux, Nisus and Euryalus, Damon and Pythias, par nobile fratrum, host, Amphitryon, Boniface, guest, visitor, prot_eg_e, amici probantur rebus adversis, ohne bruder kann man leben nicht ohne Freund, best friend, my well-spring in the wilderness, conocidos muchos amigos pocos, friend more divine than all divinities, vida sin amigo muerte sin testigo.