Definition of "forsooth"

A fit man, forsooth, to governe a realme!

a. 1628 (date written), John Hayward, The Life, and Raigne of King Edward the Sixt, London: […] [Eliot’s Court Press, and J. Lichfield at Oxford?] for Iohn Partridge, […], published 1630

[F]or certes, ſayes he, / I haue already choſen my officer, and what was he? / Forſooth, a great Arithmeticion, [...]

c. 1603–1604 (date written), William Shakespeare, The Tragœdy of Othello, the Moore of Venice. […] (First Quarto), London: […] N[icholas] O[kes] for Thomas Walkley, […], published 1622, [Act I, scene i], page 1

‘Saint forsooth!’ said ill-natured Mrs. Brady.

1844 January–December, W[illiam] M[akepeace] Thackeray, “My Pedigree and Family.—Undergo the Influence of the Tender Passion.”, in “The Memoirs of Barry Lyndon, Esq. [The Luck of Barry Lyndon.]”, in Miscellanies: Prose and Verse, volume III, London: Bradbury and Evans, […], published 1856

The four boys pumped up their hate to hissing steam. Harmless, quotha. Innocent, forsooth.

1959, Anthony Burgess, Beds in the East (The Malayan Trilogy), published 1972, page 596

Her eyes widened. She squeaked a bit. "Don't tell me she caught you bending again?" "Bending is right. I was half-way under the dressing-table. You and your singing," I said, and I'm not sure I didn't add the word "Forsooth!" Her eyes widened a bit further, and she squeaked another squeak.

1960, P[elham] G[renville] Wodehouse, chapter VIII, in Jeeves in the Offing, London: Herbert Jenkins