A mountain peak that is 14,000 feet or higher in elevation.
From 'fourteen' (Old English 'feowertiene') plus the agent suffix '-er', emerging in American English, particularly among mountaineers describing Colorado and Rocky Mountain peaks.
Colorado has 53 fourteeners—more than any other U.S. state—and climbers often try to 'bag' all of them as a personal challenge, with climbing clubs keeping official lists.
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