Etymology

cp. OIcel beinn ‘staight, direct; hospitable, helpful, accommodating’ < PGmc *baina-. The ulterior etymology is obscure, though it is often linked to the n. OIcel bein, OE bān etc. ‘bone’, or the tribal name OE Bāningas in Widsith.  

PGmc Ancestor

*baina-

Proposed ON Etymon (OIcel representative)

beinn 'straight, direct; hospitable, helpful, accommodating'
(ONP beinn (2) (adj.))

Other Scandinavian Reflexes

Far beinur, Icel beinn, Norw bein

OE Cognate

Phonological and morphological markers

ON /ei/ &lt; PGmc */ai/

Summary category

A1bc

Attestation

Fairly numerous in ME from c1300, mainly N/NM; increasingly widespread in 15c. and MnE dial usage.

Occurrences in the Gersum Corpus

Gaw 1092, 2158; Pe 807; Cl 1511; Pat 136; Erk 181; WA 323

Bibliography

MED bain (adj.) , OED bain (adj., n. and adv.) , HTOED , EDD bain (adj. adv.), Dance bayn, Bj. 40, 282, 306, de Vries beinn, Mag. beinn (2), Heid. (-)baina*-, VEPN beinn