Wiktionary
portolans
n. (plural of portolan English)
Usage examples of "portolans".
Some of these were the portolans used by merchant mariners in navigating, trading, living along the coasts.
True, I had read more of geography and studied more maps, charts, and portolans than most, and I had sailed what to Moslems were unknown seas, yet I was woefully ignorant of so much I needed to know.