by word of mouth idiom
口头上的
in speech but not in writing
All the orders were given by word of mouth so that no written evidence could be discovered later. 所有命令都是口头传达的，所以事后找不到任何书面证据。
江苏热线英汉汉英双解词典包含207361条英汉翻译词条，涵盖了常用英语单词及词组短语的翻译及用法，是英语学习的必备工具。