purr

nouns

a low vibrating sound typical of a contented cat
purr
is a type of (narrower)
the sudden occurrence of an audible event
"the sound awakened them"
sound

verbs

make a soft swishing sound
"the motor whirred"; "the car engine purred"
birr, purr, whir, whirr, whiz, whizz
indicate pleasure by purring; characteristic of cats
make vibrant sounds, purr