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
köken: From Byzantine Greek τρελός (trelós), from Koine Greek τρηρός (trērós), from Ancient Greek τρήρων (trḗrōn). The chess sense is a semantic loan from French fou.
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”).
çekim: karşılaştırma bolondabb · üstünlük legbolondabb
köken: Borrowed from a Slavic language. Compare Polish błąd (“mistake”), Russian блуд (blud, “fornication”), from Proto-Slavic *blǫdъ. Compare also unrelated German blöd.