An old or elderly woman. The phrase refers to the fact that such women's hair is sometimes a bluish color. I'm always surrounded by blue hairs at the podiatrist's office—I'm the youngest one there by about 50 years.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. an old lady, especially one whose hair is tinted blue. The cruise was nice but sort of dull because of all the bluehairs aboard.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.