Q: When did “dumb” go from meaning “mute” to “stupid”?
A: To begin at the beginning, the word “dumb” has been traced back to dheubh-, a prehistoric Indo-European root indicating confusion, stupefaction, or dizziness, according to John Ayto’s Dictionary of Word Origins.
“The notion underlying dumb is of sensory or mental impairment,” Ayto writes, adding that “two strands of meaning” developed when the term showed up in ancient Germanic languages: “slow-wittedness” and “the inability to speak.”
In Old English and Old Saxon, for example, dumb meant unable to speak, while in Old High German (spelled tumb or tump), it meant stupid, speechless, or deaf, according to the Chambers Dictionary of Etymology.
When the word first showed up in Old English around the year 1000, the Oxford English Dictionary says, it meant “destitute of the faculty of speech.” The first citation is a reference to a dumbne man in the West Saxon Gospels.
The English word “dumb” didn’t develop its stupid sense until the 19th century, according to Ayto, “presumably under the influence of” the German dumm and the Dutch dom, adjectives meaning stupid.
The OED has two 18th-century citations by the English Roman Catholic priest Alban Butler for “dumb” meaning stupid. But we feel that the examples, from The Lives of the Saints (1756), are ambiguous.
The first definite Oxford example of “dumb” meaning stupid is from The Pilot: A Tale of the Sea, an 1823 novel by James Fenimore Cooper: “‘They’re a dumb race’ said the cockswain.” (A sailor is referring to a soldier here.)
And here’s a blatantly sexist example from the February 1892 issue of Harper’s Magazine: “My, but men are dumb. A woman would have caught on long ago.”
By the way, most standard dictionaries consider it offensive to use the term “dumb” for some someone unable to speak.
A usage note in The American Heritage Dictionary of the English Language (5th ed.) adds that the use of the terms “mute” and “deaf-mute” for people unable to speak is also “now usually considered objectionable.”
“Unlike blind and deaf, which are straightforward terms that need not be avoided out of fear of causing offense, mute and deaf-mute have fallen out of use and are likely to evoke older stereotypes of helplessness or pitiableness,” the usage note says.
American Heritage doesn’t offer an alternative, but the online Macmillan Dictionary says the “more usual” way of referring to someone unable to speak is “speech impaired.”