1.Without companions; lone.
2.Characterized by aloneness; solitary.
3.Unfrequented by people; desolate; lonely crossroads.
4.Dejected by the awareness of being alone.
5.Producing such dejection: the loneliest night of the week.
1.Dejected because of a lack of companionship.
2.Producing such dejection: a lonesome hour at the bar.
3.Deserted; unfrequented: a lonesome valley.
Solitary; lone: a lonesome pine.
Self: He ate the meal all by his lonesome.
1.Existing, living, or going without others; alone: a solitary traveler.
2.Happening, done, or made alone: a solitary evening; solitary pursuits such as reading and sewing.
3.Remote from civilization; secluded: a solitary retreat.
4.Having no companions; lonesome or lonely.
5.Zoology: Living alone or in pairs only: solitary wasps; solitary sparrows.
6.Single and set apart from others: a solitary instance of cowardice.
1.Being apart from others; solitary.
2.Being without anyone or anything else; only.
3Considered separately from all others of the same class.
4.Being without equal; unique.
1.Without others: sang alone while the choir listened.
2.Without help: carried the suitcases alone.
3.Exclusively; only: The burden of proof rests on the prosecution alone.
alone - Dictionary definition and pronunciation - Yahoo! Education
They are all synonyms.