§116. Interesting Words

The word hydraulic combines the noun base hydr- (“water”) with the noun base aul- (αὐλος, “pipe”), adding the standard -ικος suffix. (An αὐλος was also a pipe played by a musician—a kind of ancient double oboe.) In Canadian usage, hydro has become a virtual synonym for electricity; the second element of hydro-electric is derived from ἠλεκτρον, Greek for “amber” (a substance in which static electricity was first observed).^[1] The term hydrophobia was commonly used as another name for rabies, because those who are afflicted with this disease suffer convulsions if they try to swallow water. Browse in your dictionary to discover many other English words that begin with hydr-.

Biologists will recognize πους, ποδος as the source of many names that end in -pod. A gastropod (gastr-o-pod), logically enough, is a “stomach foot”; this is a class of molluscs that includes snails, slugs, and limpets. A cephalopod (e.g., squid, octopus, cuttlefish) has “feet on its head.” An arthropod is an animal with an articulated foot (< ἀρθρον, “joint”); the phylum Arthropoda includes insects, arachnids (spiders) and crustaceans. The octopus just mentioned is a Latinized adaptation of ὀκτω-πους, “eight-feet.” The Greek form of this word makes it obvious why one should not pluralize octopus as octopi—though that incorrect plural is gaining respectability in English. The legendary Greek hero Oedipus (Οἰδι-πους) had a name that was generally thought to mean “Swollen-Foot” (he suffered from a limp, the result of a mysterious childhood injury). In his tragedy Oedipus Tyrannos (Οἰδιπους Τυραννος), Sophocles puns upon the hero’s name, suggesting that the real etymology may be “Know-Foot.” If Oedipus acquires true self-knowledge, he will realize that the secret of his identity is to be found in his own foot, deformed when he was abandoned in infancy by his parents, the King and Queen of Thebes.

An acropolis (“top city”) was a Greek fortified hill, and a necropolis (“corpse-city”) was an ancient cemetery. A metropolis was a “mother-city” (μητρ-) that continued to play a protective role toward its colony or colonies; the meaning has changed today, of course. A cosmopolis is a “world-city,” and a cosmopolite (κοσμοπολιτης, kosm-o-poli-tēs) a “citizen of the world.” We heard that Japan had planned a utopian city in the sky, to be known as Aeropolis 2001. This excellent Greek coinage is offset, unfortunately, by another less happily named Japanese utopian community that was apparently to be called Undergroundopolis.