Wiktionary
southwest by west
n. The compass point halfway between southwest and west-southwest, specifically 236.25°, abbreviated as SWbW.
WordNet
southwest by west
n. the compass point that is one point west of southwest [syn: SWbW]
Usage examples of "southwest by west".
The entrance to the bay bore southwest by west, little more than a league distant, and a great number of canoes were now putting out to us.
All those tenders and store-ships of ours are going on southwest by west to New York to make a floating depot for us.