1) and RING (or WRAP and WRING), to scrape together. North.
2) to exchange or swop. N.
·noun A quick, smart blow; a knock. II. Rap ·v To <<Hasten>>. III. Rap ·v To snatch away; to seize...
Webster's Dictionary of the English Language
To take a false oath; also to curse. He rapped out a volley; i.e. he swore a whole volley of oaths. ...
Dictionary of The Vulgar Tongue by Francis Grose
Applies to a ship on a wind, when "keep her rap-full!" means, do not come too close to the wind, or ...
The Sailor's Word-Book