WordReference Random House Learner's Dictionary of American English © 2026
-plex-, root.
WordReference Random House Unabridged Dictionary of American English © 2026- -plex- comes from Latin, where it has the meaning "fold.'' It is related to the root -plic-. This meaning is found in such words as: complex, duplex, multiplex, perplex, Plexiglas, plexus.
-plex,
- a combining form meaning "having parts or units'' of the number specified by the initial element, occurring originally in loanwords from Latin (duplex;
quadruplex);
recent English coinages ending in -plex, esp. denoting structures with a given number of dwelling units, are probably in part new formations with this suffix and in part based on the noun complex: fourplex;
eightplex;
Cineplex;
Metroplex.
- Latin -plex, -plic- (akin to plicāre to fold, bend, plectere to plait, braid; see -fold) + -s nominative singular ending
'plex' also found in these entries (note: many are not synonyms or translations):
-plex
- AIDS-related complex
- Electra complex
- Metroplex
- Oedipus complex
- Orestes complex
- basement complex
- brachial plexus
- castration complex
- celiac plexus
- centuplicate
- cervical plexus
- complex analysis
- complex carbohydrate
- complex fraction
- complex ion
- complex machine
- complex number
- complex plane
- complex sentence
- complex variable
- complice
- compound-complex sentence
- conjugate
- coordination compound
- culture complex
- diplex
- duplex
- duplex apartment
- duplex house
- duplex lock
- duplex process
- duplex pump
- extended complex plane
- fold
- fourplex
- googolplex
- half-duplex
- herpes simplex
- immune complex
- inclusion complex
- inferiority complex
- lumbar plexus
- major histocompatibility complex
- military-industrial complex
- multiplex
- plexal
- plexiform
- plexor
- quadplex