(1):

(n.) A thin cake made of flour and other ingredients.

(2):

(v. t.) To seal or close with a wafer.

(3):

(n.) A thin cake or piece of bread (commonly unleavened, circular, and stamped with a crucifix or with the sacred monogram) used in the Eucharist, as in the Roman Catholic Church.

(4):

(n.) An adhesive disk of dried paste, made of flour, gelatin, isinglass, or the like, and coloring matter, - used in sealing letters and other documents.