david_megginson, Old Norse "vík" meant cove or inlet (c.f. placenames like "Narvik" and "Reykjavik").
Scandinavian pirates who did hit-and-run raids from the water in the early Middle Ages were sometimes called "Víkingar" (cove people).
It's a modern English affectation to apply the "Viking" label to all early-Medieval Scandinavians (influenced by 19th-century German romaniticism??).
The Anglo-Saxons rarely used the term, preferring "Dene" (Danes) or "Norðmenn" (Northerners) for all Scandinavians.
