Word of the Day: Avuncular
And so, avunculus was the term used for one's maternal uncle, one's mother's brother. It was the diminutive of avus, a 'grand old man' on that side, normally one's maternal grandfather (one's mother's father).
I suppose that distinguished it from a carbuncle, which by similar formation meant 'a small glowing coal' and thus 'an inflamed red spot'. It was also used to describe garnets and rubies. And pimples. Hur hur.