monomania (n.)youdaoicibaDictYouDict[monomania 词源字典]
"insanity in regard to a single subect or class of subjects," 1820, probably on model of earlier French monomanie, from Modern Latin monomania, from Greek monos "single, alone" (see mono-) + mania (see mania).[monomania etymology, monomania origin, 英语词源]