swoon (n.)

c. 1300, suowne, suun, "state of unconsciousness," probably from Old English geswogen "in a faint," past participle of a lost verb *swogan (see swoon (v.)).

c. 1200, "to become unconscious," probably from a lost Old English verb *swogan (as in Old English aswogan "to choke"), of uncertain origin. Compare Low German swogen "to sigh." Related: Swooned; swooning.