Lacking companions or companionship:
— A lonely fisherman stood on a tuft of gravel.
— A lonely soul.

synonyms: alone, lone, solitary.

Roget 87: one, sole, single, solitary, unitary; individual, apart, alone; kithless^†.    unaccompanied, unattended; solus [Lat.], single-handed; singular, odd, unique, unrepeated^†, azygous, first and last; isolated etc. (disjoined) 44; insular.    monospermous^†; unific^†, uniflorous^†, unifoliate^†, unigenital^†, uniliteral^†, unijocular^†, unimodal [Math.], unimodular^†.    lone, lonely, lonesome; desolate, dreary.    insecable^†, inseverable^†, indiscerptible^†; compact, indivisible, atomic, irresolvable^†.    ... show more

Marked by dejection from being alone:
— Felt sad and lonely.

synonym: lonesome.

Polish: samotny, opuszczony

Characterized by or preferring solitude:
— A lonely existence.

synonyms: lone, solitary.

Polish: samotny

Devoid of creatures:
— A lonely crossroads.

synonyms: solitary, unfrequented.

Roget 893: secluded, sequestered, retired, delitescent^†, private, bye; out of the world, out of the way; the world forgetting by the world forgot" [Pope]. snug, domestic, stay-at-home.    unsociable; unsocial, dissocial^†; inhospitable, cynical, inconversable^†, unclubbable, sauvage [Fr.], troglodytic.    solitary; lonely, lonesome; isolated, single.    estranged; unfrequented; uninhabitable, uninhabited; tenantless; abandoned; deserted, deserted in one's utmost need; unfriended^†; kithless^†, friendless, homeless; lorn^†, forlorn, desolate.    unvisited, unintroduced^†, uninvited, unwelcome; under a cloud, left to shift for oneself, derelict, outcast.    banished etc. v.. ... show more