Source : Webster's Revised Unabridged Dictionary (1913)

Yex \Yex\, v. i. [OE. [yogh]exen, yesken, AS. giscian to sob.]
   To hiccough. [Written also {yox}, {yux}.] [Obs. or Prov.
   Eng.]

         He yexeth and he speaketh through the nose. --Chaucer.

Yex \Yex\, n. [AS. geocsa a sobbing, hiccough. Cf. {Yex}, v. i.]
   A hiccough. [Written also {yox}, and {yux}.] [Obs. or Prov.
   Eng.] ``The excessive yex.'' --Holland.