Existing, living, or going without others; alone: a solitary traveler. See Synonyms at alone. Happening, done, or made alone: a solitary evening; solitary pursuits such as reading and sewing. Remote from civilization; secluded: a solitary retreat. Having no companions; lonesome or lonely. Zoology Living alone or in pairs only: solitary wasps; solitary sparrows. Single and set apart from others: a solitary instance of cowardice. A person who lives alone; a recluse. Solitary confinement.