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Word of the Day

Learn a new word every day! The Dictionary.com team of language experts carefully selects each Word of the Day to add some panache to your vocabulary.


momentous

[moh-men-tuhs]

adjective

of great or far-reaching importance or consequence.

Explanation

Momentous, “of great or far-reaching importance or consequence,” is based on the noun moment and the adjective-forming suffix -ous. Moment comes from Latin mōmentum, literally meaning “motion” and figuratively signifying an influential element, such as a point in time. The mō- element of mōmentum comes from the verb movēre, “to move.” Movēre is the direct source of move, while its stem mōt- is found in motion and motor, and mō- also appears in mobile. Momentous was first recorded in English circa 1650. EXAMPLE OF MOMENTOUS USED IN A SENTENCE Serena Williams has achieved many momentous wins in her historic career, including a record setting number of Grand Slam titles. For another momentous word, find out what we chose as the 2022 Word Of The Year!

utilidor

[yoo-til-i-dawr]

noun

an insulated network of pipes and cables, used to convey water and electricity in communities situated in areas of permafrost.

Explanation

Utilidor, “an insulated network that conveys water and electricity in frozen areas,” is a portmanteau of utility and corridor. Utility ultimately comes from Latin ūtī (stem ūs-), “to use,” which is also the source of usual, usurp, and utensil. Corridor comes from Italian corridore (also corridoio), based on correre, “to run,” from Latin currere; for more examples of currere’s descendants in English, check out the Word of the Day corsair. Utilidor was first recorded in English in the late 1950s. EXAMPLE OF UTILIDOR USED IN A SENTENCE In northern cities such as Iqaluit, Utqiagvik, and Yellowknife, utilidors provide a useful lifeline during the dark, frozen winter months.

oleoresinous

[oh-lee-oh-rez-uh-nuhs]

adjective

consisting of drying oils and resins that usually have been cooked.

Explanation

Oleoresinous, “consisting of drying oils and resins,” is a compound of oleo-, “oil”; resin; and -ous, a suffix roughly meaning “full of, consisting of.” Oleo- comes by way of Latin oleum or olīvum, “oil, olive oil,” from Ancient Greek élaion (dialectal élaiwon), which derives from elaíā (dialectal elaíwā), “olive.” For the reason why these Ancient Greek words are inconsistent about the letter w, check out the recent Word of the Day oenology. Resin comes via Latin rēsīna from Ancient Greek rhētīnē, of uncertain origin. Oleoresinous was first recorded in English in the mid-1840s. EXAMPLE OF OLEORESINOUS USED IN A SENTENCE She distilled turmeric to create the oleoresinous varnish for the custom coatrack.

cistvaen

[kist-vahyn]

noun

a prehistoric sepulchral tomb or casket.

Explanation

Cistvaen, “a prehistoric sepulchral tomb or casket,” comes from Welsh cist faen, “stone box, stone chest.” Cist comes via Latin cista, “box, chest,” from Ancient Greek kistē. Faen is a mutated form of maen, “stone,” a Cornish relative of which is also part of the Word of the Day dolmen. In Welsh, as in many Celtic languages, the first consonant of a noun or adjective mutates in a variety of contexts, including in some compound words; this is why the m in maen (pronounced like “main” or “mine”) becomes the “softer” f in faen (pronounced like “vain” or “vine”). Cistvaen was first recorded in English in the first decade of the 19th century. EXAMPLE OF CISTVAEN USED IN A SENTENCE While dolmens are aboveground homes for the prehistoric dead, the Celts once used shallow cistvaens as burial pits.

algorithm

[al-guh-rith-uhm]

noun

an ordered set of instructions applied repeatedly to data to solve a problem or accomplish a task.

Explanation

Algorithm is a variant of algorism and ultimately comes from Arabic al-Khwārizmī, which refers to the 9th-century mathematician Muḥammad ibn Mūsā al-Khwārizmī. In this name, Khwārizm refers to an area of Central Asia now divided between Turkmenistan and Uzbekistan. Algorism became algorithm because of the influence of Ancient Greek arithmós, “number,” as in arithmetic. Algorithm was first recorded in English in the 1690s. EXAMPLE OF ALGORITHM USED IN A SENTENCE The data scientist applied a simple algorithm and solved the frustrating puzzle in less than 3 seconds.