Lacking companions or companionship:
— He was alone when we met him.
— She is alone much of the time.
— The lone skier on the mountain.
— A lonely fisherman stood on a tuft of gravel.
— A lonely soul.

synonyms: alone, lonely, 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

Characterized by or preferring solitude:
— A lone wolf.
— A lonely existence.

synonyms: lonely, solitary.

Polish: samotny

Being the only one; single and isolated from others:
— The lone doctor in the entire county.
— A lonesome pine.

synonyms: lonesome, only, sole, solitary.