bo·sun   Pronunciation Key  (bsn) n.   Variant of boatswain.

Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

bo'sun n : a petty officer on a merchant ship who controls the work of other seamen
 [syn: boatswain, bos'n, bo's'n, bosun]