Etymology
Advertisement
disorder (v.)

late 15c. (Caxton), "destroy or derange the order of, throw into confusion," from dis- "not" (see dis-) + order (v.). Replaced earlier disordeine (mid-14c.), from Old French desordainer, from Medieval Latin disordinare "throw into disorder," from Latin dis- + ordinare "to order, regulate," from ordo (genitive ordinis) "row, rank, series, arrangement" (see order (n.)). Related: Disordered; disordering.

Related entries & more 
Advertisement
major (adj.)

c. 1300, majour, "greater, more important or effective, leading, principal," from Latin maior (earlier *magios), irregular comparative of magnus "large, great" (from PIE root *meg- "great"). From 1590s as "greater in quantity, number, or extent." Used in music (of modes, scales, or chords) since 1690s, on notion of an interval a half-tone "greater" than the minor; of modern modes, "characterized by the use of major tonality throughout," by 1811. Major league, in baseball, is attested by 1892.

Related entries & more 
disorder (n.)

1520s, "lack of regular arrangement;" 1530s, "tumult, disturbance of the peace;" from disorder (v.). Meaning "an ailment, a disturbance of the body or mind" is by 1704.

Related entries & more 
major (v.)

of a college or university student, "focus (one's) studies," 1910, American English, from major (n.) in sense of "subject of specialization" (by 1890). Related: Majored; majoring. Earlier as a verb, in Scottish, "to prance about, or walk backwards and forwards with a military air and step" [Jamieson, 1825] a sense derived from the military major.

Related entries & more 
major (n.)

military rank above captain and below lieutenant colonel, 1640s, from French major, short for sergent-major, originally a higher rank than at present, from Medieval Latin major "chief officer, magnate, superior person," from Latin maior "an elder, adult," noun use of the adjective (see major (adj.)).

His chief duties consist in superintending the exercises of his regiment or battalion, and in putting in execution the commands of his superior officer. His ordinary position in the line is behind the left wing. [Century Dictionary, 1897]

The musical sense is attested by 1797.

Related entries & more 
Advertisement
major-general (n.)

"military officer next in rank below a lieutenant-general," 1640s; see major (n.) + general (n.).

Related entries & more 
major-domo (n.)

also majordomo, "man employed to superintend a household, especially that of a sovereign or other dignitary," 1580s, via Italian maggiordomo or Spanish mayordomo, from Medieval Latin major domus "chief of the household," also "mayor of the palace" under the Merovingians, from Latin maior "greater" (see major (adj.)) + genitive of domus "house" (from PIE root *dem- "house, household").

Related entries & more 
attention deficit disorder (n.)
(abbreviated ADD), introduced as a diagnosis in the third edition of the "Diagnostic and Statistical Manual of Mental Disorders" (1980), from attention in the "power of mental concentration" sense. Expanded to attention deficit hyperactivity disorder ("the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone;" ADHD) in DSM-III (1987).
Related entries & more 
muss (v.)

"to make untidy, put in a state of disorder," 1837, American English, probably a variant of mess in its sense of "to disorder." It was attested earlier (1830) as a noun meaning "disturbance, state of confusion." Related: Mussed; mussing.

Related entries & more 
parasympathetic (adj.)

in reference to major divisions of the nervous system, 1905, from para- (1) "beside" + sympathetic.

Related entries & more