Z is for Zigur

"Zigur? I don't recognize it. Where did you find this word, lad?"

"Here, in Thoughts on the Akallabeth."

"Oh. Probably Adûnaic, then. I've a small grammar on it somewhere—oh, here it is." Bilbo drew a slim volume from a shelf and leafed through it, and his expression became grim. "Oh, I see. Not good, my boy. Zigur means wizard or sorceror, and was the title granted the Lord of Mordor when he was captured by Ar-Pharazôn and taken back to Númenor as prisoner. It's best not to name Sauron the Cruel, lest you draw his Eye your way!"