purr

Short definition from Wiktionary

Verb

1. 1
   To make a vibrating sound in its throat when contented or in certain other conditions.
2. 2
   To say (something) in a throaty, seductive manner.
3. 3
   To make a vibrating throaty sound, as from pleasure.
4. 4
   To spend time enjoying and expressing pleasure (over something); to coo; to enthuse.
5. 5
   To make a low and consistent rumbling sound.

Noun

1. 1
   The vibrating sound made by a cat in its throat when contented.
2. 2
   A throaty, seductive sound of pleasure made by a person.
3. 3
   The low consistent rumble made by an engine at slow speed

Interjection

1. 1
   Vibrating sound made by a cat.
2. 2
   Alternative form of period.