"sideshow freak," by 1911, U.S. carnival and circus slang, perhaps a variant ofgeck, geke "a fool, dupe, simpleton" (1510s), apparently from Dutchgek or Low Germangeck, from an imitative verb found in North Sea Germanic and Scandinavian meaning "to croak, cackle," and also "to mock, cheat" (Dutchgekken, Germangecken, Danishgjække, Swedishgäcka). Comparegowk.

Green's Dictionary of Slang credits "one Wagner, of Charleston, West Virginia, who had a celebrated touring snake-eating act" as the popularizer of the name for the particular style of "wild man" act in which a performer (often suggested to be something sub-human) would eat or bite apart live snakes, bugs, chickens, etc.

At the highest point in the street was an empty store room in front of which, perched upon a large box, was a showman who was frantically calling in husky voice and waving hands, “He eats ‘em alive, he eats ‘em alive! O, yes, gentlemen, come right in and see the ‘Wild man from Samar’ — from the deep jungles of the far off Philippines! He eats rats, bugs and snakes alive! He eats ‘em alive, he eats ‘em alive! Only ten cents to see the wild man — walk right in, etc.” […] 

Inside the empty store room were a dozen people gazing at the wild man who was confined in a cage in the rear end under a dim light, while a second showman stood just in front of this cage expatiating upon the wonderful nature and shocking habits of the untamed creature before them. The wild man had rather long red hair and beard, and was clad in an old coffee sack, and at frequent intervals would seize a whisp of straw from the pile on which he was seated and go through the motion of eating it, or would search in the straw as if for live food such as had been described as being his favorite diet by his master at the door. But finding none, he would fly into a fury and seize the cage as if to tear his way out. Then the keeper would cry out to the crowd to stand back — “Back, back gentlemen! Iloilo is dangerous when angry — don’t you see the crowd angers him? He’s hungry — we have not given him his supper yet — the supply of snakes gave out this afternoon — he's furious!” and striking the cage with a large iron poker he shouted, “Down Ilo, down!” 

“Iloilo” having been successfully calmed, the exhibition went on for a short while till the last of the sightseers departed and the officers were left alone with the showman at the door. Stepping down from his box he exclaimed to the keeper inside, “Well, Bill, I guess the show's over in this town,” and invited them inside. 

There, as soon as they had agreed to close the exhibition, the wild man caught the cage (an old hickory crockery crate painted black) and pitched it off over his head, and asked for a bottle of beer, several of which he consumed before he clothed himself and disappeared.

[Chaplain C.Q. Wright, “The Wild Man from the Philippines”The Sailor’s Magazine, July 1913.]

By 1949 it was also defined as "any disliked person." In the 1970s the term gained currency as an insult for a kind of worthless, wimpy but pretentiously macho person, popularized by the catchphrase of pro wrestler "Classy" Freddie Blassie (1918-2003) who described all his enemies as "pencil neck geeks." Blassie had picked up the word when he began wrestling as a circus performer in the 1930s. After his retirement he released a novelty record titledPencil Neck Geek, which became a hit on the Dr. Demento Show.

You see, if you take a pencil that won't hold lead,

Looks like a pipe cleaner attached to a head,

Add a buggy whip body with a brain that leaks,

You got yourself a grit eatin', pencil neck geek.

[Song "Pencil Neck Geek." By Johnny Legend (Martin Margulies) and Pete Cicero, 1977.]

By 1980, geek was used in teenager slang in reference to a "weird person" or a "studious person" and perhaps influenced byfreak in this sense. The original freak show origins of the word were still widely known and the concept was colored by these associations, such as a geek being unclean, uncouth, disfigured, violent, etc. Throughout the 1980s the term was always used insultingly, even by studious people and tech-lovers; often interchangeable withwuss,dork,dipshit, etc.

I could not believe Bob Mack’s review of the new Danzig LP,How the Gods Kill [Spins, August ’92]. It’s not right for you to say that Glenn Danzig is a “comic book-collecting geek born in Jersey.” He is much more than that. He does what he believes in and believes in what he does. I collect comic books, and I am not a geek. Bob Mack, I hope you die at the hands of Lucifer.

Chris Allen

Fort Worth, Texas

[Letter to the editor from SPIN Magazine, Nov. 1992.]

In the popular 1984 filmSixteen Candles, Anthony Michael Hall's girl-crazy, tech-loving, socially despised character was only credited with the name "The Geek" and the term's popularity was boosted. The filmRevenge of the Nerds was released the same summer, featuring similar character types, which circumstance likely contributed togeek andnerd becoming more or less synonymous.

From c. 1989 the appellation became neutral in college slang, taking on a sense of "a person having knowledgeability or capability." In the 1990s it was often paired with another word (film geek, computer geek, etc.) and no longer necessarily used with a sense of disparagement.

"the fruit of certain trees and shrubs which have the seed enclosed in a woody covering not opening when ripe," Middle Englishnote, from Old Englishhnutu, from Proto-Germanic*hnut- (source also of Old Norsehnot, Dutchnoot, Old High Germanhnuz, GermanNuss "nut"), from PIE*kneu- "nut" (source also of Latinnux; seenucleus).

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 mechanicalnut 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 figurativenuts 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 formnutter is attested by 1958.Nut-case "crazy person" is from 1959;nut-house "insane asylum" is by 1929. For more on this sense, seenuts. In slang,nut also meant "fashionable or showy young man of affected elegance" [OED], 1904, and in the 1910s was the male counterpart to aflapper.