Etymology

Perhaps direct from the ON adv., cp. OIcel illa ‘badly, ill’, formed on illr adj.; or derived from the ME adj. ille.

PGmc Ancestor

?*elhila- 

Proposed ON Etymon (OIcel representative)

illa ‘badly, ill’
(ONP illa (1) (adv.))

Other Scandinavian Reflexes

Far illa, Icel illa, Norw illa, Dan ilde, Sw illa

OE Cognate

Phonological and morphological markers

[syncope] (possibly diagnostic) (may not be applicable)

[ON consonant cluster assimilation] (possibly diagnostic) (may not be applicable)

Summary category

B1c

Attestation

Generally N and E in ME, but occasionally further afield (incl. PP and LB (Clg A.9)) The adj. occurs as a northernism in CT.Rv.

Occurrences in the Gersum Corpus

Gaw 346; Pe 681, 1177; Cl 73, 693, 955, etc.; WA 2308

Bibliography

MED il(le (adv.) , OED ill (adv.) , HTOED , Dance ille (b)(adv.), Bj. 171