dialling tone
noun [ C usually singular ] UK uk/ˈdaɪ.ə.lɪŋ ˌtəʊn/ us/ˈdaɪ.ə.lɪŋ ˌtoʊn/ (US dial tone)
（电话）拨号音
a continuous sound that tells you that a phone is connected to the phone system and is ready to be used
英汉双解词典收录81607条英汉双解翻译词条，基本涵盖了全部常用单词的读音、翻译及用法，是英语学习的有利工具。