Tay

Origin

From Middle French teie, and its source, Latin tēca, thēca, from Ancient Greek θήκη ("covering, sheath").

Full definition of tay

Noun

1. (obsolete) The outer membrane of the brain.
• 1485, Sir Thomas Malory, Le Morte Darthur, Book XXI:ryght so he smote hys fadir, Kynge Arthure, with hys swerde holdynge in both hys hondys, uppon the syde of the hede, that the swerde perced the helmet and the tay of the brayne.----