Any of various cylindrically-shaped cells in the retina that respond to dim light.
sleeper cellRead more in this article about some frequently asked questions and fun facts related to our definitions.
Who Invented The Crossword?Arthur Wynne is usually credited with inventing the crossword. His first puzzle, called a word-cross, was published in December 1913 in the New York World. But there may have been other predecessors to the crossword: in England in the 19th century and an Italian version called per passare il tempo, which means “to pass the time.” Word crosses eventually became known as crosswords, and their creators …
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.