"have (a document) legalized by a notary," 1930 (implied in notarized), from notary + -ize. Related: Notarizing.
Entries linking to notarize
notary n.
c. 1300, notarie, "a clerk, a personal secretary; person whose vocation was making notes or memoranda of the acts of others who wished to preserve them, and writing up deeds and contracts," from Old French notarie "scribe, clerk, secretary" (12c.) and directly from Latin notarius "shorthand writer, clerk, secretary," from notare, "to note," from nota "shorthand character, letter, note" (see note (n.)).
Meaning "person authorized to draw up and authenticate contracts and other legal instruments" is from mid-14c.; especially in notary public (late 15c.), which has the French order of subject-adjective. Related: Notarial.
-ize
word-forming element used to make verbs, Middle English -isen, from Old French -iser/-izer, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.
The variation of -ize and -ise began in Old French and Middle English, perhaps aided by a few words (such as surprise, see below) where the ending is French or Latin, not Greek. With the classical revival, English partially reverted to the correct Greek -z- spelling from late 16c. But the 1694 edition of the authoritative French Academy dictionary standardized the spellings as -s-, which influenced English.
In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the Times of London, and Fowler, -ise remains dominant. Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise). American English has always favored -ize. The spelling variation involves about 200 English verbs.