'Undergarments' in the Bible

The priest is to put on his linen robe and linen undergarments. He is to remove the ashes of the burnt offering the fire has consumed on the altar, and place them beside the altar.

He is to wear a holy linen tunic, and linen undergarments are to be on his body. He must tie a linen sash around him and wrap his head with a linen turban. These are holy garments; he must bathe his body with water before he wears them.