A long, T-shaped, wide-sleeved tunic worn by men and women in the Roman Empire, beginning in the 3rd century CE. Dalmatics were decorated with tapestry-woven roundels and vertical bands (clavi). In the Medieval church, the dalmatic became  a liturgical vestment. It is worn today by clergy in the the Catholic, Anglican, Lutheran, Methodist and other churches. Web resource here.

Woman in orant pose wearing a dalmatic. Cubiculum of the Veiled Lady, Catacomb of Priscilla, Rome. 3rd century CE.