Peter Gilliver, the eminent lexicographer with the Oxford English Dictionary whose book I mentioned last time, quoted this word in an interview a couple of weeks ago. He said he had found it when young in a children’s dictionary that was full of such unusual words.
I looked for the word in Google Books, where I found several works which explained it in terms such as “a common lipogranulomatous inflammation of the sebaceous glands of the eyelids, most often the meibomian glands.” Some works also noted that it’s sometimes known as a hordeolum. In confusion, I visited Dr Gilliver’s wonderful online repository of knowledge, in which chalazion is defined as “a small pimple or tubercule; especially one on the eyelid, a stye.”
Several medical experts tell me that these definitions confuse a chalazion with a stye. A chalazion is caused by blockage of the meibomian glands, which make a lubricant for the eye. This may result in a small pimple. A stye or hordoleum is a bacterial infection of the glands that typically leads to inflammation.
Chalazion is the diminutive of Greek chalaza for almost any lump, including a small hailstone and a pimple. The OED helpfully pointed me to its entry for chalaza, which stated that in English it’s a zoological term for “Each of the two membranous twisted strings by which the yolk-bag of an egg is bound to the lining membrane at the ends of the shell.” Few of us will ever need to use it, but it’s good to know it exists.
Hordeolum derives from the Latin word for barley grains. However, the name of the meibomian glands isn’t from a classical language but derives from a seventeenth-century German anatomist named Heinrich Meibom.