ABC (n.)youdaoicibaDictYouDict[ABC 词源字典]
"the alphabet," late 13c., abece. Sense "rudiments or fundamentals (of a subject)" is from late 14c. From 1944 (in a "Billboard" headline) as a shortening of American Broadcasting Company. Related: ABCs.[ABC etymology, ABC origin, 英语词源]
basics (n.)youdaoicibaDictYouDict
"rudiments or fundamentals of anything," by 1934, from basic. Also see -ics. Phrase back-to-basics was in use by 1975.
fundamental (adj.)youdaoicibaDictYouDict
mid-15c., "primary, original, pertaining to a foundation," modeled on Late Latin fundamentalis "of the foundation," from Latin fundamentum "foundation" (see fundament). In music (1732) it refers to the lowest note of a chord. Fundamentals (n.) "primary principles or rules" of anything is from 1630s.
fundamentalist (adj.)youdaoicibaDictYouDict
1920 in the religious sense, from fundamental + -ist. Coined in American English to name a movement among Protestants c. 1920-25 based on scriptural inerrancy, etc., and associated with William Jennings Bryan, among others. The original notion might have been of "fundamental truths."
Fundamentalism is a protest against that rationalistic interpretation of Christianity which seeks to discredit supernaturalism. This rationalism, when full grown, scorns the miracles of the Old Testament, sets aside the virgin birth of our Lord as a thing unbelievable, laughs at the credulity of those who accept many of the New Testament miracles, reduces the resurrection of our Lord to the fact that death did not end his existence, and sweeps away the promises of his second coming as an idle dream. It matters not by what name these modernists are known. The simple fact is that, in robbing Christianity of its supernatural content, they are undermining the very foundations of our holy religion. They boast that they are strengthening the foundations and making Christianity more rational and more acceptable to thoughtful people. Christianity is rooted and grounded in supernaturalism, and when robbed of supernaturalism it ceases to be a religion and becomes an exalted system of ethics. [Curtis Lee Laws, "Herald & Presbyter," July 19, 1922]
Fundamentalist is said (by George McCready Price) to have been first used in print by Curtis Lee Laws (1868-1946), editor of "The Watchman Examiner," a Baptist newspaper. The movement may have roots in 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. The words reached widespread use in the wake of the contentious Northern Baptist Convention of 1922 in Indianapolis. In denominational use, fundamentalist was opposed to modernist. Applied to other religions since 1956 (earliest extension is to the Muslim Brotherhood).
A new word has been coined into our vocabulary -- two new words -- 'Fundamentalist' and 'Fundamentalism.' They are not in the dictionaries as yet -- unless in the very latest editions. But they are on everyone's tongue. [Address Delivered at the Opening of the Seminary, Sept. 20, 1922, by Professor Harry Lathrop Reed, "Auburn Seminary Record"]
grounding (n.)youdaoicibaDictYouDict
late 14c., "action of establishing," verbal noun from ground (v.). Meaning "instruction in fundamentals" is from 1640s. Sense of "background of a design" is from 1882.
nut (n.)youdaoicibaDictYouDict
"hard seed," Old English hnutu, from Proto-Germanic *hnut- (cognates: Old Norse hnot, Dutch noot, Old High German hnuz, German Nuss "nut"), from PIE *kneu- "nut" (cognates: Latin nux; see nucleus). Sense of "testicle" is attested from 1915. Nut-brown is from c. 1300 of animals; c. 1500 of complexions of women.

Meaning "crazy person, crank" is attested from 1903 (British form nutter first attested 1958; nut-case is from 1959); see nuts. American English slang sense of "amount of money required for something" is first recorded 1912. The nut that goes onto a bolt is first recorded 1610s (used of other small mechanical pieces since early 15c.). Nuts and bolts "fundamentals" is from 1960.