• synonyms


noun Mathematics.
  1. a curve described by the equation y = a sin x, the ordinate being proportional to the sine of the abscissa.
Show More

Origin of sinusoid

First recorded in 1815–25; sinus + -oid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for sinusoid


  1. any of the irregular terminal blood vessels that replace capillaries in certain organs, such as the liver, heart, spleen, and pancreas
  2. another name for sine curve
Show More
  1. resembling a sinus
Show More

Word Origin for sinusoid

C19: from French sinusoïde. See sinus, -oid
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 sinusoid

1823 in mathematics; 1900 in physiology, from sinus + -oid. Related: Sinusoidal.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper

sinusoid in Medicine


(sīnə-soid′, -nyə-)
  1. Any of the venous cavities through which blood passes in various glands and organs, such as the adrenal gland and the liver.
Show More
  1. Resembling a sinus.
Show More
Related formssi′nu•soidal (-soidl) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.