word of the day

The English language is large--Webster's and OED have about half a million entries. The average speaker of English knows between five and ten percent of that many (caveat: the definitions of 'entry' and 'word' in these are probably not entirely comparable). TestYourVocab.com reckons the average person who takes their test (who are probably rather above the population average) knows around 30,000 words (and they estimate my vocabulary at 35,200 words).

In reading, it's very common to come across words that are unfamiliar. Sometimes because an author is intentionally reaching for an unusual word, to give a sense of estrangement to the writing, and sometimes purely by chance. Certain kinds of writing are more likely to feature unfamiliar words: in my experience, scifi and fantasy are particularly heavy in odd words, probably for the sake of estrangement, and translated fiction is, too, probably due to the translator trying to capture some difference in sense in a foreign word.

So, here I will record some of the less-familiar words and phrases I come across, whether they're entirely new to me, or just stand out for their rarity or for being used in an unusual context.

Unless otherwise noted, quoted definitions are from the English Wiktionary.

actinic

Jagged, actinic flashes of lightning illuminated the desperate struggle, flash-freezing the shouting mass of weirdly dressed, sword-wielding fighters into stroboscopic scenes out of Dante's Inferno.

related to actinism, "That property of electromagnetic radiation that leads to the production of photochemical effects"
Occurs every 19 million words in American English, but once in 1.5 million in scifi and fantasy.
Aesculapian

Kirk's reply was noncommittal. "Maybe my presence is required for spiritual reasons, Bones. We don't know much about Orion culture, you know. Still," he added, forestalling another Aesculapian outburst, "I find myself agreeing with you."

Relating to medicine. Aesculapius is the Greek god of medicine. It's an Aesculapian outburst because McCoy is a doctor, I guess.
beldame

"I'm dancing with you to keep from being devoured by them," he nodded toward a group of Court beauties languishing in his direction. "I can't dance just with beldames, Elspeth has to take other partners, and the only Heralds I can trust not to try to carry me off are Keren, Sheri, and you. And those other two don't dance."

Arrow's Flight (1987-09)
A dated word for "an old woman, particularly an ugly one," though in this case I think Kris does not intend to call the women ugly.
In modern American English, beldame occurs once in about 110 million words, though in science fiction and fantasy it's much more common, appearing about once in seven million words.
chalcedony

True, the floating motes did vary in brightness and intensity, as did the pale swirls of chalcedony-colored nebulae that formed a backdrop for the white spheres.

No reason to use a fifty-cent word when a five-dollar word will do. Chalcedony is a stone which, in fact, comes in many colors. But Foster means a whitish variety, like this.
Occurs every 29 million words in American English, but once in 9 million in scifi and fantasy.
dolmen

The old guy beating at the door to use us as sacrifices because he was possessed by an ancient spirit after stumbling upon an old dolmen deep in the forest of the island.

A large stone tomb, like this.
Occurs every 22 million words in American English, but once in 6.5 million in scifi and fantasy.
flivver

Next morning... having purchased an old suit and an even more antiquated flivver, Superman carries out the first step in his plan.

a car, particularly an old or cheap one
Occurs every 22 million words in American English, but once in 770,000 in scifi and fantasy.
meerschaum

It was made of some light, ivory-colored wood that shone like fine Meerschaum.

A white stone.
Occurs every 32 million words in American English, but once in 5 million in scifi and fantasy.
omphalos

From the omphalos a powerful beam probed the ash-laden sky.

Here, the center or hub of the dish, but the word (which means 'navel' in Greek) has a more specific meaning.
Occurs every 18 million words in American English, but once in 2 million in scifi and fantasy.
rutilated quartz

The head, or such Kirk considered it, was a milky opaque crystalline substance resembling rutilated quartz.

A rather pretty stone.
Terpsichorean

Almost embarrassed, Devna made a slight bow and disappeared into the crowd, leaving the dance floor free for others to try their Terpsichorean skill.

Relating to dancing. Terpsichore was the Greek muse of dance.
Occurs every 110 million words in American English.
truck farmer

"Dr. Hamon Dell, world's foremost biochemist--and truck farmer," Curt muttered as he swung the car off the highway.

A 'truck farm' is "A small-scale farm intermediate between a garden and a full-scale farm involving the use of tractors or livestock."
Occurs every 20 million words in American English.