nostril（鼻の穴）は「鼻＋穴」。後ろ半分は thrill（スリル）と同じ語から来ていた

The English word for the holes in your nose is "nostril." It is a very old word. In Old English, more than 900 years ago, people said "nosthyrl." "Nosu" meant nose, and "thyrl" meant hole.

So a nostril is just a "nose hole." The old word for "hole" also gave English a verb that meant "to push through." That verb later became "thrill," the excited feeling you get on a roller coaster.

Some English words hide parts that people stopped using long ago. Take "nostril." In Old English it was "nosthyrl," from "nosu" (nose) and "thyrel" (hole). The word for "hole" also produced a verb meaning "to pierce," and in Middle English that verb turned into "thrill."

So the holes in your nose and the excitement of a roller coaster share an ancestor. Other words work the same way. A "nightingale" is a bird that sings at night, and its name comes from "niht" (night) and "galan" (to sing). "Garlic" combines "gar" (spear) and "leac" (leek), probably because a piece of garlic looks like the tip of a spear.

Dictionaries can show how a word was built, even when its pieces no longer mean anything on their own. Two major dictionaries trace "nostril" to the Old English "nosthyrl," a compound of "nosu" (nose) and "thyrel" (hole). From the same word for "hole," Old English formed "thyrlian," to pierce. In Middle English this became "thirlen" and then "thrillen," the source of "thrill."

Oxford calls "thirl" a dialect word, so most speakers have no reason to link a nose with excitement. Other common words hide old parts in the same way. "World" goes back to a Germanic compound meaning "age of man," and its first part is the "wer" in "werewolf." In Old English, "bridegroom" was "brydguma," bride plus "guma," man, and the ending was later reshaped to look like "groom."

Some of these stories are firmer than others. Oxford says the "were" in "werewolf" has usually been identified with "wer." The earwig got its name from an old belief that it crawls into people's ears, and the story that it eats into the brain is false. Japanese has a parallel in "mabuta," eyelid, whose "ma" is an old form of "me," eye.