§126. Greek Number Words in English

Greek ordinal adjectives regularly use the connecting vowel omicron: E prototype (prot-o-type, “first imprint”), Deuteronomy (deuter-o-nomy, “second law”). This same linking vowel is found in derivatives of mon– (μονος, “only,” a quasi-numerical form that often provides the concept of “one”): monolithic, monomorphic, monomania, monopoly. Of course, no linkage is needed if the second base begins with a vowel: protagonist (πρωτ-αγων-ιστης, “first combatant”^[1]), monocular (G mon– + L oculus + L –aris). Unlike the ordinals, most Greek cardinal numbers have stems or bases that already end in vowels, and therefore do not show that omicron link: dyarchy (“two rule”), tripod (“three foot”), pentameter (“five measure”), Decalogue (δεκα + λογοι = Ten Commandments).

Relative to Latin, Greek number words have had limited influence on English, being perhaps most familiar in the fields of plane and solid geometry. Here are two such groups:

-γωνον (γωνια, gōnia, “angle”) > E -gon: tetragon, pentagon, hexagon, octagon, trigonometry (τριγωνομετρια, tri-gōn-o-metria, “triangle measure”);

-ἑδρον (ἑδρα, hedra, “seat,” “base”) > E -hedron: tetrahedron (a three-dimensional solid), hexahedron (e.g., a cube), octahedron, dodecahedron (12), polyhedron.

Students of literature will recognize the words dimeter, trimeter, pentameter, hexameter, all of which combine numerals with metron to count the “measures” in a verse of poetry. A triptych (πτυχη, “fold”; = L triplex), is an altarpiece or other work of art in three sections. Since antiquity, the Olympic games have had a pentathlon (ἀθλον, “contest”; cf. ἀθλητης, E athlete); today we have a heptathlon and a decathlon.