word-of-mouth
adjective uk/ˌwɜːd.əvˈmaʊθ/ us/ˌwɝːd.əvˈmaʊθ/
口头的，口传的
given or done by people talking about something or telling people about something
We get most of our work through word-of-mouth recommendations. 我们大部分工作都是通过人们口头推荐得到的。
word-of-mouth publicity 通过口头推荐方式的宣传