Dictionary.com
definitions

space sickness

noun Pathology.

a complex of symptoms including nausea, lethargy, headache, and sweating, occurring among astronauts under conditions of weightlessness.

Origin of space sickness

First recorded in 1950–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for space sickness

space sickness

noun

the nausea that people can experience in the gravity-free environment of space
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
space sickness in Medicine

space sickness

n.

Motion sickness caused by sustained weightlessness during space flight, usually accompanied by disturbance of the inner ear.
Related formsspace′sick′ (spās′sĭk′) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.