noun

• (anatomy) Any of the many small fluid-filled sacs located at the point where a muscle or tendon slides across bone. These sacs serve to reduce friction between the two moving surfaces.
  "A bursa over the anterior aspect of the upper end of the tibia, between the patellar tendon and the tubercle of the tibia, is sometimes enlarged, and may be mistaken for synovitis of the joint."
• (religion) A parament about twelve inches square in which the folded corporal is kept in for reasons of reverence.
  "In solemn mass the deacon brings the book of the Missal to the side of the epistle, then goes backward behind the celebrant; the sub-deacon, indeed, goes to the gospel side, where he cleanses the chalice, fits it with the purifacatory, covers it with the paten and pall, folds the corporal, replaces it in the bursa, and puts it in the chalice covered with a veil, which he places on the altar or over the credentia, as before."