Definition of "fut"

Nay, pre-thee, fut, feere not, he's no edge-toole; you may jest with him.

1601, John Marston, What You Will

My father compounded with my mother under the dragon's tail, and my nativity was under Ursa Major; so that it follows, I am rough and lecherous. Fut, I should have been that I am, had the maidenliest star in th firmament twinkled on my bastardizing.

1606, William Shakespeare, (King Lear):

S'fut, thou liest in thy throte, thou knewst me as well as my selfe.

1611, George Chapman, May Day