Know how to use "fewer" and "less"? Find out.


[ri-lak-sin] /rɪˈlæk sɪn/
noun, Biochemistry, Pharmacology
a polypeptide hormone produced by the corpus luteum during pregnancy that causes the pelvic ligaments and cervix to relax during pregnancy and delivery.
1925-30; relax + -in2 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
British Dictionary definitions for relaxin


a mammalian polypeptide hormone secreted by the corpus luteum during pregnancy, which relaxes the pelvic ligaments
a preparation of this hormone, used to facilitate childbirth
Word Origin
C20: from relax + -in
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
Cite This Source
relaxin in Medicine

relaxin re·lax·in (rĭ-lāk'sĭn)
A female hormone secreted by the corpus luteum that helps soften the cervix and relax the pelvic ligaments in childbirth.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Encyclopedia Article for relaxin

a hormone produced by the ovaries during pregnancy that causes pelvic and cervical expansion and relaxation. It inhibits muscular contractions of the uterus that would cause natural abortion of the developing child, stimulates the growth of the glands in the breasts that are responsible for milk production, and increases the amount of water in the uterus. The hormone is found only in pregnant females, and its activities last only for 24 hours after birth.

Learn more about relaxin with a free trial on
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source

Word of the Day

Difficulty index for relaxin

Few English speakers likely know this word

Word Value for relaxin

Scrabble Words With Friends