PAP

(shadh, shodh, "breast" (Ezekiel 23:21); mastos, "the breast" (Luke 11:27; 23:29; Revelation 1:13)): The English word, which goes back to Middle English "pappe" (see Skeat, Concise Etymological Dictionary of the English Language, 327) and is now obsolete, has been replaced in the Revised Version (British and American) by "breast." The Hebrew word signifies the "female breast"; the Greek word has a wider signification, including the male chest.

From the International Standard Bible Encyclopedia
Edited by James Orr, published in 1939 by Wm. B. Eerdmans Publishing Co.