Meaning of portolano

por•to•la•no

Pronunciation: (pôr"tl-ä'nō, pōr"-), [key]
— pl. -nos, -ni
  1. a descriptive atlas of the Middle Ages, giving sailing directions and providing charts showing rhumb lines and the location of ports and various coastal features. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.