duplex

Adjective

• allowing communication in opposite directions simultaneously
  • duplex system
    
  • duplex telephony
    

• (used technically of a device or process) having two parts
  • a duplex transaction
    

Noun

• an apartment having rooms on two floors that are connected by a staircase

• a house with two units sharing a common wall

Verb

• change into a duplex

Related words

• Synonyms: 
  duplex apartment , duplex house , semidetached house