The Collaborative International Dictionary of English v.0.48:

Estuate \Es"tu*ate\, v. i. [imp. & p. p. Estuated; p. pr. &
   vb. n. Estuating.] [L. aestuare to be in violent motion, to
   boil up, burn, fr. aestus boiling or undulating motion, fire,
   glow, heat; akin to Gr.? to burn. See Ether.]
   To boil up; to swell and rage; to be agitated. --Bacon.
   [1913 Webster]