tutoyer

[too-twah-yey; French ty-twa-yey]

verb (used with object), tu·toy·ered or tu·toy·ed

[too-twah-yeyd] /ˌtu twɑˈyeɪd/, tu·toy·er·ing

[too-twah-yey-ing] /ˌtu twɑˈyeɪ ɪŋ/.

to address (someone), especially in French, using the familiar forms of the pronoun “you” rather than the more formal forms; address familiarly.

Origin of tutoyer

1690–1700; < French, to address as tu and toi (the familiar singular forms for “you” in French)

I should not have recognized her, and I don't dare to tutoyer the young lady!
Strong as Death
Guy de Maupassant
And it depends a great deal upon circumstances whether it is affection or insult to tutoyer a stranger.
Hester, Volume 1 (of 3)
Margaret Oliphant
I was half inclined to array myself in drab, and tutoyer the first of the body I chanced to encounter in my walks abroad.
Mystic London:
Charles Maurice Davies
And during the sixteen months of his studentship he grew sufficiently familiar with some of his fellow-students even to tutoyer.
Odd Bits of History
Henry W. Wolff