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.
2: an anatomical structure having the form of a spot differentiated from surrounding tissues: asa: macula acusticab: a small yellowish area lying slightly lateral to the center of the retina that is made up mostly of cones, plays a key role in visual acuity, and has the fovea at its centerâcalled also macula lutea, yellow spot.