phrase: sui generis

When reading I often find myself bemoaning the fact that I've never studied Latin.  The Latin phrase of the day is sui generis,¹ which more or less means "in a class of its own." Apparently generis is the genitive case of genus (which we should all know from taxonomy) and sui means "self" or in this case "of him/her/itself."

1. I came across this phrase in a discussion of Scottish author Alasdair Gray and his work.