Definition of "mountain sickness" []

• Altitude sickness brought on by the diminished oxygen pressure at mountain elevations. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "So short of breath are they that we dared not send them over-mountain, for the mountain sickness would have killed them."