Learning by word of mouth is a method of acquiring knowledge or skills through listening to stories, conversations, and other forms of communication. It is an ancient form of learning that has been used for centuries and is still used today. The two crossword solutions for the term 'learn by word of mouth' are 'HEAR' and 'hearof'. HEAR is a four letter word meaning to perceive sound, while hearof is a six letter word meaning to have knowledge of something through hearing about it.