[ gdw]
For the interpretation of the Middle English gloss wanster (read elsewhere as wasthere, and hence waschere) as a popular name for ‘wagtail’, see OED sub washer n.1 (4.a) and MED washer(e n. (b). The etymology of the Anglo-Norman word, unique to some of the Bibbesworth manuscripts, is obscure. It is not clear from where AND1’s original definition ‘wheatear’ (a similar small bird, but from the Oenanthe genus) derives.