Grape vine and Word of mouth

Grape vine noun - Any of numerous woody vines of genus Vitis bearing clusters of edible berries.

Word of mouth and grape vine are semantically related. In some cases you can use "Word of mouth" instead a noun phrase "Grape vine".

Word of mouth noun - Gossip spread by spoken communication.

Grape vine and word of mouth are semantically related. Sometimes you can replace phrase "Grape vine" with "Word of mouth", this phrases are similar.