From Middle English bishiten, bischiten, from Old English besċītan (“to befoul”), equivalent to be- + shit. See also beshite.
beshit (third-person singular simple present beshits, present participle beshitting, simple past and past participle beshit or beshat)
- (transitive, possibly vulgar or offensive) To soil with excrement; shit all over.
1562, John Heywood, The Proverbs, Epigrams, and Miscellanies of John Heywood, page 89:
- He looked like one that had beshit the roast.
1760, Thomas Brown, “Advice to Dr. Oates”, in Works Serious and Comical in Prose and Verse, page 243:
- Your heart must need be grip'd and full of stitches,
And you may well thro' fear beshit your britches.
2003, Jim Harrison, Off to the Side:
- Man has an inexhaustible ability to beshit his environment, with politicians well in the lead.
2010, Howard Jacobson, The Making of Henry, ISBN 1446413063, page 12:
- He will beshit himself in a public place.