n., pl., -mies.
The condition of having three copies of a given chromosome in each somatic cell rather than the normal number of two.
trisome tri'some' n.
trisomic tri·so'mic adj.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
