Some Data About 'Datum'

One of the more subtle ways that the data-driven world has changed our language is through the usage and frequency of existing words. It’s not just new coinages like blog or internet or new meanings for compounds like smartphone or for you page or even touch grass. The verb access, as in “how do I access the wi-fi,” for example, was once so rare that our Unabridged edition of 1961 didn’t even acknowledge its existence; now we all probably use it daily. Such frequency has made it feel not just plausible but standard and correct. That’s how language evolves. Familiarity breeds contentedness, at least with the words that we use.

Data is a primary word in seemingly every part of our world today. Before the computer age, data was one of many technical and scientific words borrowed from Latin during the 1600s, and understood as a plural form. These words came to English at a time when Latin was a standard subject in any schoolroom, from the elementary to the university level. The meaning of the singular form datum was something close to “fact” or “detail” and was most often used in scholarly contexts, which remains true today. Data has entered a more popular register, largely leaving datum behind.

Other words much more frequently encountered in their Latin plurals include bacteria (the singular is bacterium) and arcana (the singular is arcanum).

Some of the words in this category are flipped in their popularity, known better as singular forms than plural, including stadium (stadia), auditorium (auditoria), and atrium (atria). Pluralizing these words in the conventional manner for English words, by adding an -s, is also standard. Stadiums is not only just fine, it’s now much more common.

Words that have kept their Latin plurals are disproportionately found in academic contexts, like colloquium/colloquia, consortium/consortia, curriculum/curricula, erratum/errata, criterion/criteria.

At least one of these words is known equally well in both singular and plural forms: medium and media are both common, but the plural is probably not construed to be a plural of medium in this case. Their semantic territories have drifted apart.

As recently as our Unabridged edition of 1961, the definition for data was found at datum, as was the definition of arcana at arcanum and bacteria at bacterium and criteria at criterion and even media at medium. This shows how recently many of these forms have become the principal way that these words are used, but it also shows something else: the prestige and importance of Latin words as a special category in English vocabulary.

Datum is still in use today and known to both scientists and word lovers. After all, it’s playable in SCRABBLE.