word of mouth

informal oral communication: The rumor spread rapidly by word of mouth.

Origin of word of mouth

First recorded in 1545–55

word-of-mouth, adjective

But word-of-mouth and changing times soon made it a classic.

The Catch in “Catch-22” |Morris Dickstein |September 4, 2011 |DAILY BEAST
Through databases and word-of-mouth, everyone was fairly aware of who they were working with.

Porn’s New HIV Problem |Richard Abowitz |September 2, 2011 |DAILY BEAST
Word-of-mouth should be strong and this movie is likely to have what the industry calls “legs.”

Is Star Trek Now Cool? |Kim Masters |May 7, 2009 |DAILY BEAST
But it was by word-of-mouth invitation that I was in her kitchen yesterday morning.

The Little Lady of the Big House |Jack London

You might hear the warning given on radio or television, or even by word-of-mouth.

In Time Of Emergency |Department of Defense
Word-of-mouth publicity accounts for the gradual steady growth in the use of the rooms.

The Library and Society |Various
Bn Shaikh is well-apprized of word-of-mouth matters, and will inform thee of them.

The Bbur-nma in English |Babur, Emperor of Hindustan
This will be an unceremonious summary of a word-of-mouth message.

The Bbur-nma in English |Babur, Emperor of Hindustan