nut-cracker n.

"the fruit of certain trees and shrubs which have the seed enclosed in a woody covering not opening when ripe," Middle English note, from Old English hnutu, from Proto-Germanic *hnut- (source also of Old Norse hnot, Dutch noot, Old High German hnuz, German Nuss "nut"), from PIE *kneu- "nut" (source also of Latin nux; see nucleus).

Sense of "testicle" is attested by 1915 (nuts). Nut-brown "brown as a ripe, dried nut" is from c. 1300 of animals; c. 1500 of complexions of women. The mechanical nut that goes onto a bolt is first recorded 1610s, from some fancied resemblance (nut was used of other small mechanical pieces since early 15c.). The figurative nuts and bolts "fundamentals" is by 1952. The American English slang sense of "amount of money required for something" is recorded by 1912.  

Meaning "crazy person, crank" is attested from 1903; British form nutter is attested by 1958. Nut-case "crazy person" is from 1959; nut-house "insane asylum" is by 1929. For more on this sense, see nuts. In slang, nut also meant "fashionable or showy young man of affected elegance" [OED], 1904.

Old English cracian "make a sharp noise, give forth a loud, abrupt sound," from Proto-Germanic *krakojan (source also of Middle Dutch craken, Dutch kraken, German krachen); the whole group is probably ultimately imitative. Related: Cracked; cracking.

From c. 1300 as "to burst, split open" (intransitive), also transitive, "to cause to break into chinks." From 1785 as "break or crush into small pieces." Of the voice, "change tone suddenly," as that of a youth passing into manhood, c. 1600. Meaning "to open and drink" (a bottle) is from 16c.

From early 14c. as "to utter, say, speak, talk freely," especially "speak loudly or boastingly" (late 14c.). To crack a smile is from 1835, American English; to crack a joke is by 1732, probably from the "speak, say" sense. To crack the whip in the figurative sense is from 1886. Get cracking "go to work, start doing what is to be done" is by 1937.

What is a crack in English? A chat! The synonym is as perfect as possible; yet the words are subtly distinguished by a whole hemisphere of feeling. A chat, by comparison "wi' a crack," is a poor, frivolous, shallow, altogether heartless business. A crack is, indeed, only adequately to be defined as a chat with a good, kindly, human heart in it .... [P.P. Alexander, notes to "Last Leaves," Edinburgh, 1869]