(1):

(superl.) Alone, or in want of company; forsaken.

(2):

(superl.) Sequestered from company or neighbors; solitary; retired; as, a lonely situation; a lonely cell.

(3):

(superl.) Not frequented by human beings; as, a lonely wood.

(4):

(superl.) Having a feeling of depression or sadness resulting from the consciousness of being alone; lonesome.