purr
purr
noun
A low, continuous, vibrating sound made by a cat, indicating contentment.
"She loved the soft purr of her kitten."
verb
To make a low, continuous, vibrating sound, typically by a content cat.
"The cat purred contentedly on her lap."
Thesaurus
Synonyms: whir, whirr, whiz, birr, whizz, make vibrant sounds