More thread creep- wik, wick, wike, wyk(e) in Old English, Saxon, means dwelling place inc. hamlet, dairy farm, enclosure, etc.; vic (cf. L. vicus), street, row of houses, etc.
Viking-r is Icelandic, Old Norman.
Old English wic, wicing, prob. from a creek or inlet, a different word from the wik meaning dwelling place; thus Hagar and friends probably named by the Anglo-Frisians as people coming out of inlets of the sea- Viking was not the original name of the Vikings, but later was adopted by them. Interesting that they are known by the name applied by the people being invaded or preyed upon.

Note: The history of these words as given in the OED should be taken cum grano salis; similarly the story in the etymological dictionary which was compiled, I have heard (I don't have a copy of the Etymology, so can't check), by different editors. Both are interpretations of the evidence remaining to us.
In other words, the explanation found by Greg probably is just as likely!