[ gdw]
The primary sense of this word, found in Continental French and Latin as ‘small ear’ (and hence ‘any ear-shaped object’), does not seem to be attested in Anglo-Norman. In the dictionaries of Continental French, the sense ‘plough-ear’ is listed only by TL (from the same Bibbesworth attestation) and is absent from the relevant entries in the DMF and FEW. The DMLBS, in contrast, includes it (as sense 2b). The same sense is also attested sub oreille.
The Anglo-Norman variant spelling with ‘s’ instead of ‘r’ is only found in Nom and appears to be un-etymological.