Definition of "nibs"

Vera, you are a gleam of brilliant modernity in our dim old cave of antiques — and their nibs, our ancestors." Peter waved disrespectfully to the portrait

1919, Robert Nichols, “The Secret”, in The Century, page 734

Betsey Reed, Her Nibs, was just as witty and quaint as usual, sitting in state in her wheel chair and dominating everything and everybody.

1920, Oreola Williams Haskell with Ida Husted Harper, Banner bearers: tales of the suffrage campaigns, page 345

You may also know that, during intermission, Paul and Linda were summoned to a room behind the royal box for a private chat with her nibs.

1983 June 5, “OFFSTAGE”, in Chicago Tribune

"Your Nibs," I panted, "I am sent by the machine gunner man to tell you that ... "Please don't call me Your Nibs, and knock before you come in next time,

2004, Michael Arnold, A game with dice, page 59