Word Origin & History
c.1300, from O.Fr. rebelle (12c.), from L. rebellis "insurgent, rebellious," from rebellare "to rebel, wage war against," from re- "opposite, against," or perhaps "again" + bellare "wage war," from bellum "war." The noun is attested from c.1400. Meaning "supporter of the American cause in the War of
Independence" is from 1775; sense of "supporter of the Southern cause in the American Civil War" is attested from April 15, 1861.
"The Southern troops, when charging or to express their delight, always yell in a manner peculiar to themselves. ... The Confederate officers declare that the rebel yell has a particular merit, and always produces a salutary and useful effect upon their adversaries. A corps is sometimes spoken of as a 'good yelling regiment.' " [A.J.L. Fremantle, "Three Months in the Southern States," 1863]
The verb (late 14c.) is from O.Fr. rebeller, from L. rebellare. Related: Rebellion (mid-14c.).