Definition of "befoul"

These heights are a desirable retreat, for less picturesque reasons—as an escape from a compound of vile smells perpetually arising from a great harbour full of stagnant water, and befouled by the refuse of innumerable ships with all sorts of cargoes: which, in hot weather, is dreadful in the last degree.

1846, Charles Dickens, “Avignon to Genoa”, in Pictures from Italy, London: […] Bradbury & Evans, […], page 34

At last, what with a round of blasphemy, and the whole crowd with clay pistols belching smoke and fire and slander of their neighbours, and the floor already befouled with dregs and spittle, I feared lest viler deeds should happen, and craved to depart.

1897, Robert Gwynneddon Davies (translator), The Sleeping Bard by Ellis Wynne, London: Simplkon, Marshall & Co., Part I

Only the four walls of his home still stood, blackened and smoking with the sluggish, stinking smoke that befouled the sea-wind.

1983, Mary Stewart, chapter 5, in The Wicked Day‎, New York: William Morrow, page 53

There was a pool of perfect water. / […] No cattle / Had slobbered their muzzles in it / And befouled it.

1997, Ted Hughes, Tales from Ovid, “Echo and Narcissus” in Paul Keegan (ed.), Ted Hughes: Collected Poems, New York: Farrar, Straus and Giroux, 2003, p. 919

For its an ill Bird will befoule her own Nest […]

1666, George Alsop, A Character of the Province of Mary-Land‎, London: Peter Dring, Preface

“ […] But pray what smell is that? Sure your lapdog has befoul’d himself;—let me catch hold of the nasty cur, I’ll teach him better manners.”

1748, [Tobias Smollett], chapter 12, in The Adventures of Roderick Random. […], 2nd edition, volume I, London: […] J. Osborn […], page 91

For three days Pete bore himself according to his wont, thinking to silence the evil tongues of the little world about him, and keep sweet and alive the dear name which they were waiting to befoul and destroy.

1894, Hall Caine, The Manxman‎, London: Heinemann, Part 5, p. 282

“ […] you combine a vulgar atheism and an iconoclastic desire to befoul the sacred ideas of the average man or woman, collectively scorned as the bourgeoisie——”

1923, James Branch Cabell, The High Place‎, London: John Lane, Part 2, Chapter 15

There she sits before you, gentlemen, betrayed by her husband, befouled by every idle tongue that wags […]

1927, Frances Noyes Hart, chapter 5, in The Bellamy Trial‎, Garden City, NY: Doubleday, Doran & Co., published 1929, page 159