Definition of croons:
(v) :
(transitive) To hum or sing (a song or tune), or to speak (words), softly in a low pitch or in a sentimental manner; specifically, to sing (a popular song) in a low, mellow voice.
(v) :
(intransitive) To hum or sing, or to speak, softly in a low pitch or in a sentimental manner; specifically, to sing a popular song in a low, mellow voice.
(v) :
(transitive) To soothe (a person or an animal) by singing softly.
(n) :
A soft, low-pitched sound; specifically, a soft or sentimental hum, song, or tune.
(v) :
(intransitive) (Northern England, Scotland) To lament, to moan.
(v) :
(intransitive) (Northern England, Scotland) To make a continuous hollow low-pitched moan, as of cattle; to bellow, to low.