From Longman Dictionary of Contemporary Englishthrumthrum /θrʌm/ verb (thrummed, thrumming) [intransitive] CSSOUNDto make a low sound like the sound of an engine The engine thrummed into life. —thrum noun [singular] the thrum of passing cars→ See Verb table
Examples from the Corpus
thrum• The engine thrummed as we drove through the countryside.Origin thrum (1500-1600) From the sound 