What is another word for "companion"?

Roget's Thesaurus (1911) lists these synonyms for "companion": accessory, accompaniment, accompany, acquaintance, addition, adjunct, advocate, all, ally, along, alter, ambo, amigo, and, appendage, appurtenance, arm, associate, associated, association, attend, attendant, attribute, auxiliary, bear, bedfellow, best, boat, body, boon, bosom, bring, casual, chamber, cheek, childhood, chum, classman, classmate, coefficiency.