Etymology

Derived from from OE ǣghwǣr ‘everywhere’, a combination of OE ā + gehwǣr (cp. OHG eogihwār), and most authorities are satisfied with this etymon (so MED, TGD, GDS).  But in the phonetically reduced ME form, it might have been interpreted as a compound of ay ‘ever’ + where and it is therefore entirely possible that some ME speakers treated it as containing ME ay < ON ei (see ay)(OED), and hence that it ‘may owe some of its use to the influence of ay’ (McGee 321).

PGmc Ancestor

the acc. sg. of *aiwaz

Proposed ON Etymon (OIcel representative)

ey, ei 'always, eternally, forever'
(ONP ei (2) (adv.), ey (4) (adv.))

Other Scandinavian Reflexes

Icel ei, e

OE Cognate

ǣghwǣr ‘everywhere’

Phonological and morphological markers

Summary category

CC5c

Attestation

Relatively infrequent after the 13c. (and some of MED’s early attestations straightforwardly continue OE ǣghwǣr, viz. c1175(?OE) Bod.Hom.(Bod 343) <æʒhwær>); later citations are predominantly N/EM.

Occurrences in the Gersum Corpus

Gaw 599, 629, 745, etc.; Cl 228, 965, 1403; WA 781*, 3408

Another instance is introduced at Gaw 660 by some editors attempting to make sense of MS <jquere> (thus Morris, M(G), TG ai quere, Jones aywhere), but Knott (1915: 105) raises doubts about the emendation, and the form has been dealt with in a range of other ways.

Bibliography

MED ai-whēr (adv.) , OED aywhere (adv.) , HTOED , Dance ayquere, de Vries ei (1), Mag. ei (1), ey (3), Orel *aiwaz ~ *aiwiz; *xwar ~ *xwēr, Kroonen *hwar-, AEW ǣg-hwǣr, DOE ǣg-hwǣr