say it: DOO-pleks
duplex is a noun, adjective and verb meaning "a house with two units sharing a common wall". It carries 5 recorded senses.
a house with two units sharing a common wall
an apartment having rooms on two floors that are connected by a staircase
allowing communication in opposite directions simultaneously
“duplex system”
“duplex telephony”
telecommunication
change into a duplex
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for duplex come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.