both refer to movie chains (i.e., Loews, AMC Theatres) with movie theatres that screen more than one film at a time, as opposed to single-screen theatres. A multiplex has from 2 up to 16 screens, a megaplex has 16 or more screens; plex is the abbreviation for a multiplex theatre.
A morula (Latin, morus: mulberry) is an early stage embryo consisting of cells (called blastomeres) in a solid ball contained within the zona pellucida.
a solid ball of cells resulting from cleavage of a fertilized ovum. It is formed of a mass of BLASTOMERES which subsequently form a BLASTULA. morula. 1. a solid mass of cells (blastomeres) resembling a mulberry, formed by cleavage of a fertilized ovum.