normalize (v.)

c. 1500, "typical, common;" 1640s, in geometry, "standing at a right angle, perpendicular," from Late Latin normalis "in conformity with rule, normal," in classical Latin "made according to a carpenter's square," from norma "rule, pattern," literally "carpenter's square," a word of unknown origin (see norm). Meaning "conforming to common standards or established order or usage, regular, usual" is attested from 1828 but probably is older than the record [Barnhart].

Meaning "heterosexual" is by 1914. As a noun meaning "usual state or condition," from 1890 (in geometry as "a perpendicular" from 1727). Sense of "a normal person or thing" is attested by 1894. Normal school "training college for teachers" (1835) is a translation of French école normale (1794), a creation of the French Republic; the notion is of "serving to set a standard." The U.S. city of Normal, Illinois, was named 1857 for the normal school established there.

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.

"act or process of making normal," 1842, from normalize + -ation. International political sense "achieving of stable relations between two countries" is recorded by 1938.