solitary

one who lives in solitude

confinement of a prisoner in isolation from other prisoners

“he was held in solitary”

of plants and animals; not growing or living in groups or colonies

“solitary bees”

lacking companions or companionship

“a solitary traveler”

characterized by or preferring solitude

“a man of a solitary disposition”

devoid of creatures

“a solitary retreat”

being the only one; single and isolated from others

“a solitary instance of cowardice”