From Hull AWE
The word chilblain (sometimes used in the collective/plural chilblains) is spelled thus, with a single '-l-' in each syllable. This is despite the fact that the root of the first syllable is chill, with two '-l-'s.
- Modern students may need to be told what chilblains are, although they were a common affliction before central heating became general. A chilblain is an itchy red swelling (a 'blain' is 'a sore', 'a blister' or some kind of pustule) on the extremities - fingers, toes and ears are the usual sites - caused by exposure to cold, exacerbated by poor circulation. It is made worse by switching too often from cold to hot, and sufferers were well-advised not to warm their hands or feet in front of an open fire.
- In Early Modern English, there was a special term for a chilblain on the heel, particularly if ulcerated or open, a kibe. (The same spelling may be seen as a transliteration of the food 'kibbeh', something like a croquette, served in traditional Arab and North African cuisine.) Shakespeare uses the word, for example in Hamlet (1601), V i 150: "The age is grown so picked that the toe of the peasant comes so near the heel of the courtier, he galls ['hurts'] his kibe" and "Where lies that? If 'twere a kibe / 'Twould put me to my slipper" (The Tempest, II i 276).
- You may also want to see AWE's note on -l - -ll-.