Used attributively before another noun to denote something involved in relaying or functioning as a relay.
Translations
The relay antenna sits atop the hill to extend coverage.
Ретрансляционная антенна стоит на вершине холма, чтобы расширить зону покрытия.
Definitions
Relating to, involving, or functioning as a relay, especially for receiving and retransmitting signals or messages. The relay antenna sits atop the hill to extend coverage.