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.
morÂ·dant. 1. A substance capable of combining with a dye and the material to be dyed, thereby increasing the affinity or binding of the dye; for example, alum, a mordant commonly used to promote staining with hematoxylin. 2. To treat with a mordant.