[ sahy-nuh-soid ]
/ ˈsaɪ nəˌsɔɪd /

noun Mathematics.

a curve described by the equation y = a sin x, the ordinate being proportional to the sine of the abscissa.

Origin of sinusoid

First recorded in 1815–25; sinus + -oid Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for sinusoid

/ (ˈsaɪnəˌsɔɪd) /


any of the irregular terminal blood vessels that replace capillaries in certain organs, such as the liver, heart, spleen, and pancreas
another name for sine curve


resembling a sinus

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

Medical definitions for sinusoid

[ sīnə-soid′, -nyə- ]


Any of the venous cavities through which blood passes in various glands and organs, such as the adrenal gland and the liver.


Resembling a sinus.

Other words from sinusoid

si′nu•soidal (-soidl) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.