eel

Picture an Old English speaker pointing into dark river water and saying ǣl: the word was already ancient, compact, and wriggly, much like the animal itself. It descends from reconstructed Proto-Germanic *ælaz or *ēlaz, but here etymologists reach an unusually firm dead end: no certain relatives outside the Germanic family have been found. That means eel may be a linguistic fossil from a time before surviving written records, preserved in forms such as Dutch aal and German Aal. By the 1520s, English speakers had begun using eel figuratively for a slippery or evasive person—the fish’s physical talent for escaping became a character judgment. Modern slang dictionaries even record eel as an insult for a disliked, manipulative person, so every time someone “slithers” out of responsibility, an ancient fish is still doing the talking.