psycho, lunatic, psychopath (a person who is psychotic or otherwise insane). · nut (a person who acts in a bizarre or dangerous manner) · state of being angry; madness; being in a rash (often used when speaking about children)
köken: From Middle Dutch geck (“madman”). Earlier origin uncertain, but perhaps from an imitative verb also found in Swedish gäcka (“to mock”). Cognate with German Geck, Jeck, English geek (see etymology there).
aile: gek als een deur, gek als een ui, gekke Henkie, gekkerd, gekkig, gekmakend, gekscheren, knettergek, stapelgek
madman, lunatic · madness, insanity · enthusiast, fan
eş: 狂人, きじるし, ばか, マニア, フリーク
köken: Verbal noun of 気(き)が違(ちが)う (ki ga chigau, “to be mad”). Analyzable as 気(き) (ki, “mind, temperament, character; mood, spirit”) + 違(ちが)い (chigai, “difference; mistake”, 連(れん)用(よう)形(けい) (ren'yōkei, “stem or continuative form”) of the verb 違(ちが)う (chigau, “to differ; to be mistaken”)).
köken: From Old Swedish dāre, from Old Norse dári, Middle Low German dore, from Old Saxon *dōro, from Proto-West Germanic *dauʀō. See also German Tor; Icelandic dári, Danish dåre.
köken: From ne- (“not”) + bun (“sane”). The sense “bishop (chess piece)” is a semantic loan from French fou, from Spanish alfil, from Arabic الفيل (al-fīl, “elephant, chess bishop”).
köken: From Proto-Malayo-Polynesian *baliw (“return”), from Proto-Austronesian *baliw (“return”). Compare Central Bikol baliw, Cebuano baliw, and Maranao baloy. Doublet of ibayo.