Webster's Revised Unabridged Dictionary · 1913

Blain

Blain (blān) , noun

[Old English blein, bleyn, Anglo-Saxon blēgen; akin to Danish blegn, Dutch blein; perh. from the same root as English bladder. See Bladder.]

1.
An inflammatory swelling or sore; a bulla, pustule, or blister.
Blotches and blains must all his flesh emboss. — Milton
2.
(Farriery) A bladder growing on the root of the tongue of a horse, against the windpipe, and stopping the breath.