世界上最长的单词：色氨酸合成酶A蛋白质
MethionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysylglutamylarginyllysylglutamylglycylalanylphenylalanylvalylprolyphenylalanYlvalythreonylleucylglycylaspartylprolylglycylisoleucylglutamylglutaminylsErylleucyllysylisoleucylaspartylthreonylleucylIsoleucylglutamylalanylglycylalanylasparthlalanylleucylglutamylleucylglycylisoleucylprolylphenylalanylseRylaspartylprolylleucylalanylaspartylglycylpRolylthreOnylisoleucylglutaminylasPfraginylalanylthreonylleucylarfinylalanylphenylalanylalanylalanylglycylvalythreonylprolylalanylglutaminylcysteinylphenylalanylglutamylmethionylleucylalanylleuOylisoleucylarginylglutaminyllysyhistidylprolylthreonylisoleucylprolylisoleucylglycylleucylmethionyltyrosylalanylasparaginylleucylvalylphenylalanylasparaginyllysyglycylisoleucylaspartylglutamylphenylalanylthrosylalanylglutaminylcysteinylglutamyllysylvalylglycylvalylaspartylserylvalylleucylvalylalnylaspartylvalylprolylvalylglUtaminylglutamylserylalanylprolylphenylalanylarginylglutaminylalanylalanylleucylarginylhistidylasparaginyvalylalanylprolylisoleucylprolylisoleucylphenylalanylisoleucylphenylalanylisoleucylcysteinylprolylprolylaspartylalanylaspartylaspartylaspartylleucylleucylarginylglutaminylisoleucylalanylseryltyrosylglycylarginylglycyltyrosylthreonyltyrOsylleucylleucylserylarginylalanylglycylvalylthreonylglycylalanylglutamYlasparainylarginylalanylalanylleucylprolylleucylasparaginylhistidylleucylValylalanyllysylleucyllysylglutamyltyrosylasparaginylalanylalanylprolylprolylleucylglutaminylglgycylphenylalanylglycylisoleucylserylalanylprolylaspartylglutaminylvalyllysylalanylalanylisoleucylaspartylalanylglycylalanylalanylglycylalanylisoleucylserylglycylserylalanylisoleucylvalyllysylisoIeucylisoleucylglutamylglutaminylHistidylasparaginyliSoleucylglutamylprolylglutamyllysylmethionylleucylalanylalanylleucyllysylvalylphenylalanylcalylglutaminylprolylmethionlysylalanylalanylthreonylarginylserine

缩写:Tryptophan synthetase A protein

还有一个pneumonoultramicroscopicsilicovolcanoconiosis
这个比起上一个好多了
是一种疾病
语源学:
Pneumono=与肺相关(拉丁语)
超=非常(拉丁语)
微观=极端小(Latin/Old英语)
silico=硅土(拉丁语)
火山=火山(拉丁语)
coni=与尘土(希腊语相关:konis,尘土)
osis=疾病/情况(希腊语)
这曾经一定是最长的词出现在一个非技术性的英语词典(来源:OED)。1936年这45封信件词第一次出现在牛津英语字典,和并且有从看上去在韦伯斯特的第三本新国际字典(在-konioisis之下供选择拼写),任意议院未删节的字典和Merriam韦伯斯特的大学字典,命名但一些。
评论家抱怨,这个词是一个技术术语(具体地,一个医学术语),并且因此不值得考虑作为"最长的词一般用法"。

意思是[医]硅酸盐沉着病,矽肺病

还有个 aequeosalinocalcalinoceraceoaluminosocupreovitriolie
它是英国医学作者爱德华.史特罗哲Dr Edward Strother，1675-1737创造的字，专用来形容英格兰格洛斯特夏布瑞斯陀这个地方的矿泉水成分。

楼上说的长单词恐惧症，学名hippopotomonstrosesquippedaliophobia ，也是个专有名词。

好吧，又翻到了两个
bababadalgharaghtakamminarronnkonnbronntonnerronntuonnthunntrovarrhounawnskawntoohoohoordenenthurnuk 这个字是由100个字母组成的。就出现在爱尔兰作家乔埃斯jamesjoyce,1882-1942作品finneganswake的扉页象征代表亚当和夏娃的堕落。
lopadotemachoselachogaleokranioleipsanodrimhypotrimmatosilphioparaomelitokatakechymenokichlepikossyphophattoperisteralektryonoptekephalliokigklopeleiolagoiosiraiosiraiobaphetraganopterygon 这个字是由182个字母组成的。它是从希腊字英译过来的英文字源出自希腊喜剧作家亚里斯多芬尼斯aristophanes,448-385的剧本the ecclesiazusae中。它是指由剩余的菜和牛肉函煮而成的辣味食物。