Definition of chants:
(v) :
To sing, especially without instruments, and as applied to monophonic and pre-modern music.
(v) :
To sing or intone sacred text.
(v) :
To utter or repeat in a strongly rhythmical manner, especially as a group.
(n) :
Type of singing done generally without instruments and harmony.
(n) :
A repetitive song, typically an incantation or part of a ritual.
(n) :
(music) A short and simple melody to which unmetrical psalms, etc., are sung or recited.