• synonyms


[ev-uh-loot or, esp. British, ee-vuh-]
noun Geometry.
  1. the locus of the centers of curvature of, or the envelope of the normals to, another curve.Compare involute(def 5).
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Origin of evolute

1720–30; < Latin ēvolūtus (past participle of ēvolvere to roll out, unfold, evolve)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for evolute

Historical Examples

  • By and by that flour-sack is going to evolute into an underskirt for me to wear under my dress when I go to school.

    The Story of Opal

    Opal Whiteley

  • This point evidently lies upon the branch zM of the evolute in Fig. 23.

  • The evolute of a curve is the curve which is the envelope of all its normals or the locus of all its centres of curvature.

  • These names are given to the curves because the end of a stretched thread unwound from the evolute will describe the involute.

  • A curve which has a given curve as evolute is called an “involute” of the given curve.

British Dictionary definitions for evolute


  1. a geometric curve that describes the locus of the centres of curvature of another curve (the involute). The tangents to the evolute are at right angles to the involute
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  1. biology having the margins rolled outwards
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Word Origin

C19: from Latin ēvolūtus unrolled, from ēvolvere to roll out, evolve
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