a communications device that allows two or more people to one is used to transmit at a time

A radiotelephone is a communications device that allows two or more people to talk using radio. There is disagreement about the definition of the term. There is a conflict between British English usage, American English usage, and historic use.

A wireless telephone, in which the signal is conveyed by radio waves.

a telephone that communicates by radio waves rather than along cables

telephony that uses transmission by radio rather than by wire