eightetethe

from The Collaborative International Dictionary of English v.0.48

Eightetethe \Eight"e*teth`e\, a. [OE., fr. AS.
   eahtate['o][eth]a; eahta eight + te['o][eth]a tenth. Cf.
   {Eighteenth}, {Tenth}.]
   Eighteenth. [Obs.]
   [1913 Webster]