(also mattins )
■ noun a service of morning prayer, especially in the Anglican Church.
↘a service forming part of the traditional Divine Office of the Western Christian Church, originally said (or chanted) at or after midnight.
Origin
ME: from OFr. matines , plural of matin 'morning', from L. matutinum , neut. of matutinus 'early in the morning', from Matuta , the name of the dawn goddess.