RhymeZone: plex definitions

Definitions of plex:

noun: (Canada) A building, such as a duplex or triplex, with a number of apartments (typically two to four) that all open directly to the outside.
noun: (computing) A designated portion of a disk, usually set up to mirror some of the contents.
noun: Clipping of multiplex. [A building or a place where several activities occur in multiple units concurrently or different times.]

(Definitions from Wiktionary)