Definition of "solitude"

Now the New Year reviving old Desires,The thoughtful Soul to Solitude retires,Where the White Hand of Moses on the BoughPuts out, and Jesus from the Ground suspires.

1859, Edward Fitzgerald, The Rubáiyát of Omar Khayyám: The Astronomer-Poet of Persia, page 2

Cranks like Rousseau made solitude glamorous, but sensible people agreed that it was really terrible.

1975, Saul Bellow, Humboldt’s Gift, New York, N.Y.: Viking Press, page 193

Mark where his carnage and his conquests cease! He makes a solitude, and calls it — peace.

1813, Lord Byron, Bride of Abydos, Canto 2, stanza 20

[S]uch an one […] recalls as a vision of Paradise the land he has learnt to love; he exaggerates the insalubrity of a northern climate; he bewails the wretched formality of our civilised life, and so, back to the distant solitudes flies his recollection like a dove to the wilderness.

1874, Georg August Schweinfurth, chapter I, in Ellen E. Frewer, transl., The Heart of Africa: Three Years' Travels and Adventures in the Unexplored Regions of Central Africa, from 1868 to 1871‎, second edition, volume I, London: Sampson Low, Marston, Low, And Searle, translation of Im Herzen von Afrika, Botanical Ardour