liturgical vestment worn in some services by Roman Catholic officiants, some Anglicans, and some Lutherans. A symbol of purity, it is a full-length, long-sleeved, usually white linen tunic secured at the waist by a cord or belt called a cincture. The equivalent vestment in the Eastern churches is the sticharion.

Derived from the long white tunic (tunica alba, or linea) commonly worn in the Greco-Roman world, the alb was retained by the Christian clergy as a vestment after secular styles began changing in the 6th century AD. In the 10th century the plain alb was decorated with embroidery on the hem and cuff, and it was later decorated with four or five rectangular patches of embroidery called parures, apparels, or orphreys. Apparels became less common in the 16th century and were replaced by lace, which eventually covered most of the garment. In the 20th century, with the Roman Catholic liturgical renewal, the plain white linen alb came back into use.