to speak to familiarly, as, in French, by using the singular forms (tu and toi) of “you” rather than the more formal plural form (vous)
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'tutoyer'
Fr < MFr < tu
(familiar form for you, thou < L: see thou1
) + toi
(acc. of tu
) + -er
, inf. ending