c. 1600, "sameness, oneness, state of being the same," from French identité (14c.), from Medieval Latin identitatem (nominative identitas) "sameness," ultimately from Latin idem (neuter) "the same" (see idem). [For discussion of Latin formation, see entry in OED.] Earlier form of the word in English was idemptitie (1560s), from Medieval Latin idemptitas. Term identity crisis first recorded 1954. Identity theft attested from 1995. Identity politics is attested by 1987.
"[I]dentity politics" [is] a phrase with notably wide currency in gay and lesbian communities. In common usage, the term identity politics refers to the tendency to base one's politics on a sense of personal identity—as gay, as Jewish, as Black, as female ..... [Diana Fuss, "Essentially Speaking," 1989]
1690s, in reference to a specific religious movement, Pietism, from German Pietismus, originally applied in derision to the movement to revive personal piety in the Lutheran Church, begun in Frankfurt c. 1670 by Philipp Jakob Spener (1635-1705). See piety + -ism. With lower-case p- and in reference generally to devotion, godliness of life (as distinguished from mere intellectual orthodoxy), by 1829.
also eurhythmic, "harmonious," 1831, from Greek eurythmia "rhythmical order," from eurythmos "rhythmical, well-proportioned," from eu "well, good" (see eu-) + rhythmos "measured flow or movement, rhythm; proportion, symmetry" (see rhythm). Related: Eurythmics (also eurhythmics), "system of rhythmical body movement to music, used as therapy or to teach musical understanding," developed by Swiss music educator Émile Jaques-Dalcroze; eurythmy.
"capacity of automatic or spontaneous movement," 1827, from French motilité (1827), from Latin mot-, stem of movere "to move" (from PIE root *meue- "to push away").