Thorn used to be a letter in both the Scandinavian and Old English tongues, representing the sound 'th'. The, that, this, there, thistle (and so on. It's rune three. Also Thor has Norse meaning of thunder.
Off subject but.. "maes" is an important part of anglo-saxon words, it can stand at the beginning of kinsman/woman, king, maiden, strength etc, but every so often "ge" precedes it, is this just some qualifying grammar? Its an interesting word, because it appears on high ridges/hills here.i.e.Maes knoll, mile from Stanton Drew and Maesbury fort.