To discomfit is (1) to throw into confusion, perplex, or embarrass; or (2) to thwart or defeat, especially in military conflict. The second sense is the original—and a handful of people insist that it is still the only correct use—but the first is more common today and is rarely questioned. The word historically doubled as a noun referring to a discomfited state, but discomfiture eventually arose to fill this role and was firmly in place by the 19th century.
Discomfort is usually a noun referring to a state of unease or pain, but it also works as a verb meaning cause discomfort. The verb is somewhat rare, though, usually giving way to the two-word phrase make uncomfortable and other synonyms.
There is much common ground between the verb discomfort and the modern sense of discomfit. Of course, those who don’t accept the newer sense of discomfit would disagree with this, but in actual usage the words are mostly synonymous. It’s possible to draw some loose distinctions between them, though: discomfiture is a mental state, while discomfort can be physical; and discomfiture in social situations often involves confusing or vexing behavior that is not necessarily unacceptable, while discomfort more often involves unacceptable, boundary-crossing behavior. But these are general, and no doubt exceptions are easily found.
A third verb, disconcert, is often lumped with discomfit and discomfort as a related source of confusion. Its main sense is disrupt the composure of. While in some narrow uses the word is not exactly synonymous with discomfit and discomfort, in practice there is often little substantive difference between them. Disconcertedness tends to go along with discomfiture and discomfort, and those states tend to go along with disconcertedness.
Upbraid no man’s weakness to him to discomfort him, neither report it to disparage him, neither delight to remember it to lessen him, or to set thyself above him. [The Rules and Exercise of Holy Living, Jeremy Taylor (1650)]
He appeared on the walls under the figure of the Roman emperor, and sent an army of gnats to sting the trunks of the elephants, and to discomfit the host of the new Senacherib. [The History of the Decline and Fall of the Roman Empire, Edward Gibbon (1780s)]
Much to our discomfit, we were so baffled by calms and light winds, that we were a fortnight in sailing three hundred miles! [A Narrative of Missionary Enterprises in the South Sea Islands, John Williams (1837)]
Quiban, the native chieftain, who had discomforted Bartholomew Columbus, was still lord of the coast. [Panama, the canal, the country and the people, Arthur Bullard (1918)]
Secretary-General Annan was, in fact, acknowledging an “evolving” international norm which was starting to discomfit the U.N. itself [Challenges of Globalization]
I know this is based on a true story, yet what discomforts me about the film is that it invokes an insidious fantasy. [ABC Online]
When a government minister says something that is not only true but also profoundly discomfiting we are surprised and even shocked. [Telegraph]
Few visitors, in short, spend enough time with the work to be discomforted by it — lest they be discomforted by it. [Mark Rothko: A Biography, James E. B. Breslin]
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