southwest by west

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The direction or point on the mariner's compass halfway between southwest and west-southwest, or 123°45′ west of due north.
• adverb & adjective Toward or from southwest by west.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The compass point halfway between southwest and west-southwest, specifically 236.25°, abbreviated as SWbW.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the compass point that is one point west of southwest