pneumonoultramicroscopicsilicovolcanoconiosis，[医]肺尘病,矽肺病（共有45个英文字母）这是目前世界上最长的正式英文单词。
词根：
pneumono- (of lung 肺的)
ultra- (beyond 越过)
micro (very small 极小的)
scopic- (of viewing or observing 观察或注意的)
silico- (of silicon 硅的)
volcano- (mountain that releases fire and ash 火山的)
coni- ( koni, of dust 尘土的)
osis-(forming the name of a disease 表示疾病)
扩展资料
网络上广泛传播的1909个字母的最长英文“单词”只是一种谬论。
原文
肌联蛋白（一种含有267种氨基酸的酶）的化学名根据英文造字规则，一共有189819个字母，全部读完需要花费约3.5小时。以下单词有1909个字母，全部读完需要花费约25分钟，是它的一类：
MethionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysylglutamylarginyllysylglutamylglycylalanylphenylalanylvalylprolyphenylalanYlvalythreonylleucylglycylaspartylprolylglycylisoleucylglutamylglutaminylsErylleucyllysylisoleucylaspartylthreonylleucylIsoleucylglutamylalanylglycylalanylasparthlalanylleucylglutamylleucylglycylisoleucylprolylphenylalanylseRylaspartylprolylleucylalanylaspartylglycylpRolylthreOnylisoleucylglutaminylasPfraginylalanylthreonylleucylarfinylalanylphenylalanylalanylalanylglycylvalythreonylprolylalanylglutaminylcysteinylphenylalanylglutamylmethionylleucylalanylleuOylisoleucylarginylglutaminyllysyhistidylprolylthreonylisoleucylprolylisoleucylglycylleucylmethionyltyrosylalanylasparaginylleucylvalylphenylalanylasparaginyllysyglycylisoleucylaspartylglutamylphenylalanylthrosylalanylglutaminylcysteinylglutamyllysylvalylglycylvalylaspartylserylvalylleucylvalylalnylaspartylvalylprolylvalylglUtaminylglutamylserylalanylprolylphenylalanylarginylglutaminylalanylalanylleucylarginylhistidylasparaginyvalylalanylprolylisoleucylprolylisoleucylphenylalanylisoleucylphenylalanylisoleucylcysteinylprolylprolylaspartylalanylaspartylaspartylaspartylleucylleucylarginylglutaminylisoleucylalanylseryltyrosylglycylarginylglycyltyrosylthreonyltyrOsylleucylleucylserylarginylalanylglycylvalylthreonylglycylalanylglutamYlasparainylarginylalanylalanylleucylprolylleucylasparaginylhistidylleucylValylalanyllysylleucyllysylglutamyltyrosylasparaginylalanylalanylprolylprolylleucylglutaminylglgycylphenylalanylglycylisoleucylserylalanylprolylaspartylglutaminylvalyllysylalanylalanylisoleucylaspartylalanylglycylalanylalanylglycylalanylisoleucylserylglycylserylalanylisoleucylvalyllysylisoIeucylisoleucylglutamylglutaminylHistidylasparaginyliSoleucylglutamylprolylglutamyllysylmethionylleucylalanylalanylleucyllysylvalylphenylalanylcalylglutaminylprolylmethionlysylalanylalanylthreonylarginylserine
辟谣
这个词在形式上是按顺序将蛋白的所有氨基酸残基的英文名排列在一起。 [1]
其真实的英文名称只有五个字母：Titin.
反驳
这个词虽然是把所有氨基酸残基的英文名排列在一起，但是它是IUPAC名。比如，一个人的基因组不属于化合物，而这个色氨酸合成酶a蛋白质正是化合物，所以可以使用IUPAC名（当然不常用就是了）。
参考资料：百度百科 - 最长的英文单词