Word Origin & History
1817, from Fr., from Sp. vasco (adj.), from vascon (n.), from L. Vascones (Vasconia was the Roman name for the up-country of the western Pyrenees), said by von Humboldt to originally mean "foresters" but more likely a Latinized version of the people's name for themselves, euskara or eskuara.
"This contains a basic element -sk- which is believed to relate to maritime people or sailors, and which is also found in the name of the Etruscans ...." [Room, "Placenames of the World," 2006]
Earlier adj. in English was Basquish (1610s).