late 14c., "means of completing; that which completes; what is needed to complete or fill up," from Old French compliement "accomplishment, fulfillment" (14c., Modern French complément), from Latin complementum "that which fills up or completes," from complere "fill up," from com-, here probably as an intensive prefix (see com-), + plere "to fill" (from PIE root *pele- (1) "to fill").
From c. 1600 as "full quality or number, full amount;" musical sense of "simple interval that completes an octave from another simple interval" is from 1873. In 16c. also having senses which were taken up c. 1650-1725 by compliment.
late 14c., fixacion, an alchemical word, "action of reducing a volatile substance to a permanent bodily form," from Medieval Latin fixationem (nominative fixatio), noun of action from past-participle stem of Latin fixare, frequentative of figere "to fasten, fix" (from PIE root *dheigw- "to stick, fix"). Meaning "condition of being fixed" is from 1630s. Used in the Freudian sense since 1910.
"make complete," 1640s, from complement (n.). Earlier in a now-obsolete sense of "exchange courtesies" (1610s), from complement (n.) in a 16c. sense "that which is added, not as necessary, but as ornamental," now going with compliment. Related: Complemented; complementing.
late 14c., "small vessel used in assaying precious metals," from Old French test, from Latin testum "earthen pot," related to testa "piece of burned clay, earthen pot, shell" (see tete).
Sense of "trial or examination to determine the correctness of something" is recorded from 1590s. The connecting notion is "ascertaining the quality of a metal by melting it in a pot." Test Act was the name given to various laws in English history meant to exclude Catholics and Nonconformists from office, especially that of 1673, repealed 1828. Test drive (v.) is first recorded 1954.
1748, "to examine the correctness of," from test (n.), on the notion of "put to the proof." Earlier "assay gold or silver" in a test (c. 1600). Meaning "to administer a test" is from 1939; sense of "undergo a test" is from 1934. Related: Tested; testing.
1963, short for Papanicolaou (1947) in reference to George Nicholas Papanicolaou (1883-1962), Greek-born U.S. anatomist who developed the technique of examining secreted cells to test for cancer.
in trigonometry, "the tangent of the complement of a given angle," a contraction of co. tangent, abbreviation of complement + tangent (n.).
1620s, "ceremonious" (a sense now obsolete in this spelling of the word), from complement (n.) + -ary. Sense of "forming a complement, mutually completing each other's deficiencies," is attested by 1794, in reference to the calendar of the French Revolution; in reference to colors which in combination produce white light, by 1814. Earlier in the sense "completing, forming a complement" was complemental (c. 1600).
