a passageway through which surplus water escapes from a reservoir, lake, or the like.

Origin of spillway

First recorded in 1885–90; spill1 + way1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for spillway

Historical Examples of spillway

  • You know its location: a mile, perhaps, from Gatun Dam and the spillway.

    Raiders Invisible

    Desmond Winter Hall

  • It also serves as a spillway over which the surplus water escapes.

    Electricity for the farm

    Frederick Irving Anderson

  • It could only race and swirl along one channel, and that was the spillway of memories.

    The Tyranny of Weakness

    Charles Neville Buck

  • Here they could erect their spillway for the control of the water in the lake above.

    The Panama Canal

    Frederic Jennings Haskin

  • The first stop was at the concrete work on the spillway dam at Miraflores.

    The Panama Canal

    Frederic Jennings Haskin

British Dictionary definitions for spillway



a channel that carries away surplus water, as from a damAlso called: wasteweir, spill
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for spillway

1889, from spill + way.

Online Etymology Dictionary, © 2010 Douglas Harper