Wood — or headland. Written Ross, Ros — the same Irish word, ros, in the spellings English gave it.
Wood — or headland: it is the Irish ros. It is written Ross, Ros in English spellings of Irish names.
ros. English spellings of the same word include Ross, Ros, because the names were written down by ear.
New Ross (Ros Mhic Thriúin), Roscommon (Ros Comáin), Carrickmacross (Carraig Mhachaire Rois).