Word of the Day

Tesseract “a four-dimensional cube” derives from Ancient Greek tésseres (also téttares) “four,” which is also the source of tessellate “to form small squares,” after the number of sides in a square, and the combining form tetra- “four,” as in tetrahedron, a figure with four faces, and tetralogy, a series of four related books or films. Tésseres comes from the Proto-Indo-European root kwetwer-, which is the source of English four, forty, fortnight, and farthing and Latin quattuor and quadri- “four” (as in quatrain, a four-line poem, and quad, a four-sided common space), quārtus “fourth” (as in quarter, which is one-fourth of a dollar), and quater “four times”  (as in quaternary “consisting of four”). Tesseract was first recorded in English in the late 1880s.

Cenotaph “a monument erected in memory of a person buried elsewhere” derives by way of Latin cenotaphium from Ancient Greek kenotáphion, literally meaning “empty tomb,” from kenós “empty” and táphos “tomb.” A common misconception is that the ceno- element of cenotaph is related to the identical combining forms ceno- (also caeno- or caino-) “new” and ceno- (also coeno-) “common,” but despite the resemblance, there is no connection. The diphthongs ai and oi in Ancient Greek, which were adapted as ae and oe in Latin, both frequently become e in American English, which can easily result in homonyms—words that sound and are spelled the same but are unrelated. A similar example occurred with the element pedo- in pedology, which can mean “soil science” when pedo- is derived from Ancient Greek pédon “soil,” or can mean “the study of child development” when pedo- is derived from Ancient Greek paîs (stem paid-) “child.” Cenotaph was first recorded at the turn of the 17th century.

Nugatory “of no force or effect” comes from Latin nūgātōrius “worthless, useless,” from the verb nūgārī “to trifle.” Nūgārī, in turn, derives from the plural noun nūgae “trifles, idle talk, frivolities,” which is also the source of nugacious, a synonym of nugatory, and nugacity, a noun that means “insignificance.” While it may seem odd that Latin features nouns such as nūgae that always appear in the plural, English is no stranger to nouns that usually or exclusively appear in plural form. Many objects that contain two component parts, such as pants, trousers, scissors, and shears, are typically limited to the plural, as are certain location-related words, such as headquarters and surroundings. Nugatory was first recorded in English at the turn of the 17th century.

Circadian “pertaining to 24-hour biological cycles” is a coinage based on two Latin terms: the preposition circā “about, around” and diēs “day.” English has also adapted circā directly (as circa) when providing estimates of dates. If you were wondering why circā resembled circle and circus, it is because all three words descend from Ancient Greek kírkos “ring, circle.” Latin diēs is also the source of day-related words such as diary, diet, and meridian; the term also has an adjective form, diurnus “daily,” which is the source of words such as diurnal and journal, as we learned about in the etymology for the recent Word of the Day selection toujours perdrix. Circadian was first recorded in English in the late 1950s.

Avgolemono “a soup made with beaten eggs, lemon juice, and chicken broth” is a loanword from Modern Greek augolémono, literally meaning “egg lemon.” Through a series of regular yet dramatic sound changes, Modern Greek augó derives from classical Greek ōión “egg,” which is the source of the combining form oo- (as in oocyte “immature egg cell”) and is distantly related to English egg and Latin ovum (as in ovary and, via Spanish, in huevos rancheros). Modern Greek lemóni, bucking the common trend of Greek words exported to the Italian peninsula, is a borrowing from Italian limone and ultimately derives from Persian līmū; from here, the word may have traveled through India and originated in Southeast Asia, perhaps in the Austronesian language family. Avgolemono was first recorded in English in the early 1960s.