See here for for a detailed explanation of how Old English wic and Latin vicus developed from a meaning of ‘exchange place ’ and became applied to any settlement where trading took place.  In Latin, vicus was used for streets and districts inside cities, and for villages outside.  Modern archaeologists have picked up vicus to be used (incorrectly) to mean ‘extramural settlement’.  In fact the historical record shows clearly that vicus was an administrative term, describing a community that aspired to Roman values, of government, religion and commerce.  Within Britain, the evidence for Roman vicus and for early English wic is concentrated around the Dover-London-Lincoln-York-Corbridge-Edinburgh corridor up the east of Britain.  For wic sites in Kent, see Durham &; Goormachtigh (2015) Archaeologia Cantiana 136, 163–176.