Definition of "southwest by south" [southwest by south]
The direction or point on the mariner's compass halfway between southwest and south-southwest, or 146°15ʹ west of due north.(noun)
Toward or from southwest by south.(adverb)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.