<p><strong>Noun</strong></p><ul><li>a person who is frequently in the company of, associates with, or accompanies another: my son and his two companions.</li><li>Synonyms: mate, partner, comrade, associate</li><li>a person employed to accompany, assist, or live with another in the capacity of a helpful friend.</li><li>a mate or match for something: White wine is the usual companion of fish.</li><li>a handbook or guide: a bird watcher's companion.</li><li>a member of the lowest rank in an order of knighthood or of a grade in an order.</li><li>Also called companion star, comes.</li><li>Astronomy: the fainter of the two stars that constitute a double star. Compare primary (def 19b).</li><li>Obsolete: a fellow.</li></ul><p><strong>Verb</strong></p><ul><li>(used with object) to be a companion to; accompany.</li></ul>