Definition of portolan in English:

portolan

(also portolano)

nounportolans, portolanos

historical
  • A book of sailing directions with charts and descriptions of harbours and coasts.

    • ‘From early times, charts called portolans (harbor guides) were available to provide details required by the coastline-hugging sailor - depth of the water, location of treacherous rocks, special landmarks, et cetera.’
    • ‘In its purest form, the portolan chart was a highly functional tool for navigation whether in the contained arena of the Mediterranean or later in the open oceans of the world.’
    • ‘On an oceanic voyage, however, especially at higher latitudes, the converging meridians on the physical globe conflicted with the parallel meridians shown on the traditional portolan chart.’
    • ‘Nonetheless, in this period the portolan chart remained very much centred on the Mediterranean and destinations easily reached from there.’
    • ‘The earliest portolan maps covered the Mediterranean and Black Sea and showed wind directions and such information useful to sailors.’

Origin

Mid 19th century from Italian portolano, from porto ‘harbour’.

Pronunciation

portolan

/ˈpɔːtəlan/