subs. phr. (common).A large stomach: spec. that of a pregnant woman. Hence BOW-WINDOWED = big-bellied; LUMPY (q.v.).
1840. MARRYAT, Poor Jack, i. He was a very large man with what is termed a considerable BOW-WINDOW in front.
184950. THACKERAY, Pendennis, xxxiv. (1884), 334. Look at that very BOW-WINDOWED man.
1889. Daily Telegraph, May 6. She was what is vulgarly called BOW-WINDOWED.