Note: It's not entirely clear these examples belong in a single entry. For sense (b), cf. MED dāsen v., and related dasedhede n., dasedli adv. and dasednesse n., though the apparent meaning (editor's gloss: 'daze, dizziness') belongs as readily to the related daswe- group ('dimness of sight,' etc.; see daswe n., daswen v., daswing ger., daswenesse n.)

Note: For sense (a), a plausible source may be found in Middle Dutch, or it may be an OE survival. Cp. OE dwæs = I. dull, foolish, stupid. II (masc.) clumsy imposter. dwæsian to become stupid dwæslic = foolish. (adv.-lice.). This group not noted in MED as a possible source for the group dasen v., dasard n. or even daswen v. Also dasewen [akin to dasen v.]. Bradley-Stratman referred dasen and dwæsian to dwæsian, but MED, following OED, refers these to ON: cp. OI dasa—etc. Bradley-Stratmann also notes (s.v. dasin) that ON dasa = (be sluggish) is MDu. dasen, dwasen (rave, be foolish), OE dwæsigean, etc. V.&V. (Jacob Verdam and Eelco Verwijs, Middelnederlandsch Woordenboek (1885-1927)), s.v. daes adj. notes that this is a form of Middle Dutch dwaes = Dutch dwaas = foolish, stupid, and points to MHG dæsic = stupid. Middle Dutch dwaes is both adj. and n. Middle Dutch forms dwas, etc. given their own entry, but connected as well. (notes per MG)