Definition: The process following the third cleavage division of the zygote during which the blastomeres maximize their contact with each other by polarization and adhesion, forming a compact ball that is held together by tight junctions; compaction segregates the inner cells of the blastocyst that form the embryo from the outer cells that form the fetal part of the placenta.
[L. compactio, fr. com-pingo, pp. com-pactus, to press together]
Search Stedman's Medical Dictionary
Examples: glitazone, GI cocktail, etc.