Oh, and another great word I have never understood or been able to find a definition of (help wanted!) - MAVEN.
Seems to be mainly used as a noun, or with a descriptor as a noun phrase, e.g. " a fashion maven". Doesn't seem to be very complimentary somehow, but for the life of me, I don't know why.
Bit like "merkin" I suppose... this rapidly changed from its original meaning to a term of insult.