noun.
A bluish discoloration of the skin and mucous membranes resulting from inadequate oxygenation of the blood.
The Century Dictionary and Cyclopedia
noun.
In pathology, a blue or more or less livid color of the surface of the body, due to imperfect circulation and oxygenation of the blood; the blue jaundice of the ancients.
the GNU version of the Collaborative International Dictionary of English
noun.
A condition in which, from insufficient aëration of the blood, the surface of the body becomes blue. See cyanopathy.
noun.
A bluediscolouration of the skin due to the circulation of blood low in oxygen.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a bluish discoloration of the skin and mucous membranes; a sign that oxygen in the blood is dangerously diminished (as in carbon monoxide poisoning)
Word Usage
"With too much deoxygenated blood in the arteries, the skin turns from pink to blue (cyanosis comes from the Greek kyanos, meaning dark blue)."