Hum and Throb

Hum verb - To be copiously supplied.

Throb and hum are semantically related. in murmur topic. In some cases you can use "Throb" instead the word "Hum" as a verb or a noun, when it comes to topics like buzz, drone, purr, be busy.

Throb verb - To expand and contract in a rhythmic manner.

Hum and throb are semantically related. You can use "Hum" instead a verb "Throb".