tother
pronoun or adjective
toth·er ˈtə-t͟hər 
variants or t'other
chiefly dialectal
: the other
Word History
Etymology
Middle English tother, alteration (resulting from misdivision of thet other the other, from thet the— from Old English thæt — + other) of other — more at that
First Known Use
13th century, in the meaning defined above