Other forms: thrumming, thrums
To thrum is to make a low steady vibrating sound. The engine thrummed, thrumming rain, a thrum of traffic.
The steadiness is what distinguishes it — a thrum goes on, where a thud stops. It is often felt as much as heard. The word was made from the sound. Note thrumming as a way of describing an atmosphere that feels charged.
1verbthrumTo make a low steady vibrating sound.
“The ship's engines thrummed beneath our feet all night.”
thrum is a sound.
An imitative word, made directly from the sound it names.
imitative of the sound.
Etymology from Wiktionary, CC BY-SA