something of a (something)
Having a lot of qualities like or associated with some particular thing or type of person. He fancies himself as something of an expert on modernism in literature, just because he studied Joyce for his master's degree. She's something of a con-artist, isn't she? There's no way this repair should cost this much!
something of a
To some extent, as in Our professor is something of an eccentric. [Early 1700s]
something of a something
quite or rather a something; something to an extent: He has something of a reputation as a sportsman.Our walk home turned out to be something of an adventure.