Q: My dictionary says “inane” is derived from inanis, the Latin term for empty. Is there an English antonym based on the same Latin root? Something like “pronane,” for example?
A: There isn’t such a word. That’s because “inane” no longer means what it did when it was adopted from Latin. It now means silly or senseless, but it originally meant empty or void.
The Latin adjective inanis (empty) and verb inanere (to empty) do have opposites—plenus (full) and implere (to fill).
You’ll recognize in them the ancestors of our words “plenty,” “plenteous,” “plenum” (a full assembly), and “plenipotentiary” (having full power).
But there’s no English antonym for “inane” that’s based on the same Latin root. Your playful suggestion, “pronane,” doesn’t exist in English, and if it did, it would mean the opposite of empty, not silly.
The Latin-derived words that look a bit like “inane” and come closest to being its opposite in meaning have different classical roots. “Animated,” for example, ultimately comes from anima, Latin for breath or soul.
The adjective “inane,” as you know, means senseless, unimaginative, insubstantial, or unintelligent. It’s used to describe someone or something that lacks sense or substance.
Of course there are lots of English words that mean the opposite. For starters, let’s simply turn around the words in the definition above: “sensible,” “imaginative,” “substantial,” and “intelligent.”
We could add many more: “smart,” “sharp,” “deep,” “profound,” “weighty,” and so on. However, we can’t think of a single word that truly does the job.
It’s interesting that a term derived from the Latin word for empty is so full of senses of one sort or another, though all of them are related to emptiness.
When “inane” showed up in English in the mid-17th century, it simply meant empty and was used to refer to abstract things.
The first citation in the OED is from Joseph Glanvill’s Lux Orientalis (1662), a book about Eastern beliefs in the existence of souls: “To have confined his omnipotence to work only in one little spot of an infinite inane capacity.”
It took a century and a half for the word to come to mean silly, senseless, or empty-headed. The OED’s first citation is from The Cenci (1819), a verse play by Shelley: “Some inane and vacant smile.”
The Chambers Dictionary of Etymology says “inane” is probably a back formation from the noun “inanity,” which showed up at the beginning of the 17th century.
(A back formation, as regular readers of the blog are aware, is a word formed by subtracting an element from an older one.)
“A similar development is found in vain and vanity,” Chambers notes, “where the noun is recorded earlier than the adjective.”
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