[1] byrði (n.) ‘boarding’: So A, C. The name has the same meaning as borð ‘ship’s side, planking’ (Falk 1912, 51). The R, Tˣ, B variant, bygði (‘frame’?), must be a derivative from the weak verb byggja, byggva ‘build’, but that word does not appear in Icelandic sources with this meaning until the C15th (see CVC: byggja).