c.1443, "primary, original, pertaining to a foundation," modeled on L.L.
fundamentalis "of the foundation," from L.
fundamentum "foundation" (see
fundament). Religious senses of
fundamentalist (1920) and
fundamentalism (1923) began in Amer.Eng. with a movement among Protestants c.1920-25 based on scriptural inerrancy, etc., and associated with William Jennings Bryan, among others.
Fundamentalist first used in print by Curtis Lee Laws, editor of "The Watchman Examiner," a Baptist newspaper.
" 'Fundamentalism' ... appears to have been used first in connexion with the (American) Northern Baptist Convention of 1920 to describe the more conservative delegates who desired 'to restate, reaffirm, and reemphasize the fundamentals of our New Testament faith.' ... Now 'Fundamentalism' ... appears to describe the bigoted rejection of all Biblical criticism, a mechanical view of inspiration and an excessively literalist interpretation of scripture." ["London Times," Aug. 25, 1955]
Garry Wills, in "Under God" (1990) traces the terms and the movement to the Presbyterian General Assembly of 1910, which drew up a list of five defining qualities of "true believers" which other evangelicals published in a mass-circulation series of books called "The Fundamentals." A World's Christian Fundamentals Association was founded in 1918. Applied to other religions, especially Islam, since 1957.
[fuhn-duh-men-tl] 
dəˈmɛn