Sui generis

Sui generis is a (post) Latin expression, literally meaning of its own kind/genus or unique in its characteristics. The expression was effectively created by scholastic philosophy to indicate an idea, an entity or a reality that cannot be included in a wider concept. In the structure "genusspecies" a species that heads its own genus is sui generis. The word is pronounced SOO-eye JEN-er-ihs or SOO-ee JEN-er-ihs; (IPA) or .