For-sōoth', adv.

adv. [A-S. forsōth, from for and sōth, sooth, truth.] In truth; in fact; certainly; very well; — often used ironically.

A fit man, forsooth, to govern a realm! Hayward.

Forsooth appears to have been formerly a term used much with and by women, in a dainty or affected way, whence such uses as the following: “The captain of the Charles had forsoothed her, though he knew her well enough, and she him.” Pepys’ Diary.

You sip so like a forsooth of the city. B. Jonson.