Definition of "centroid" [cen•troid]

• See center of mass. (noun)
• The point in a system of masses each of whose coordinates is a weighted mean of coordinates of the same dimension of points within the system, the weights being determined by the density function of the system. (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.

• "The third is the centroid, which is the intersection of the lines that go from the vertex to the midpoints of opposing lines."
• "For each signature, we calculated the gene expression centroid of the two groups of breast tumors (as determined in the original publications), and then correlated each centroid with cell line expression of the respective signature genes."
• "Search the Discussion Group history for "centroid," and you'll find lots of entries, many on nearly the same question."