Definition of "fifty" []

• The cardinal number equal to 5 × 10. (noun)
• A decade or the numbers from 50 to 59: They began playing golf in their fifties. With the sunshine, the temperature reached the fifties. (noun)
• The decade from 50 to 59 in a century. (noun)
• A fifty-dollar bill. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Lord Durham wrote, over fifty [Errata: (from final page) for _fifty_ read _forty_.] years ago, of the French Canadians: 'They are a people without a history and a literature.'"
• "The difference between never becoming fixed, and becoming fixed once in fifty is definitely not random."
• "I seemed to need to hear a word fifty times for it to register."