[pawr-tl-ah-noh, pohr-]

noun, plural por·to·la·nos, por·to·la·ni [pawr-tl-ah-nee, pohr-] /ˌpɔr tlˈɑ ni, ˌpoʊr-/.

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.

Origin of portolano

1855–60; < Italian: shipmaster's guidebook; earlier, harbor master < Medieval Latin portulānus. See port1, -ule, -an
Also called rutter.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for portolani

Historical Examples of portolani