origins
English and Scottish
From the Middle English personal name Dodde, Dudde, Old English Dodda, Dudda, which remained in fairly widespread and frequent use in England until the 14th century. It seems to have been originally a byname, but the meaning is not clear; it may come from a Germanic root used to describe something round and lumpish—hence a short, plump man.
Irish
English origin, taken to Sligo in the 16th century by a Shropshire family; also sometimes adopted by bearers of the Gaelic name Ó Dubhda (see Dowd).