Both dual and duel derive from the Latin adjective dualis, “containing two,” from Latin duo, “two.”
The English adjective dual refers to something that pertains to or consists of two parts. For example, a “dual carriageway” is a road with separate carriageways divided by a strip. An airplane or motor vehicle might have “dual controls” that can be operated by two people, an instructor and a student.
The English noun duel refers to a private fight between two persons, fought with deadly weapons in the presence of at least two witnesses. For example, “Alexander Hamilton died of a wound received in a duel with Aaron Burr.”
Duel can also be used as a verb. Duel is often used figuratively, both as noun and verb. In the context of sports, a duel can refer to a contest between two teams as well as to one between two individuals.
The similarity between the words dual and duel tempts writers to pun on them. For example:
Duel Love: a romance novel by Barbara Youree in which the love of two men for the same woman results in a duel between them.
Duel Personalities: an episode of Our Little Rascals in which Alfalfa is hypnotized into thinking he is D’Artagnan and challenges Butch to a duel.
Here are some unintentional misuses of the words dual and duel from the Web:
Incorrect: Being a duel speaker of both English and Chinese, I’m constantly looking for ways to improve my skills in both languages.
Correct : Being a dual speaker of both English and Chinese, I’m constantly looking for ways to improve my skills in both languages.
Incorrect: “They are going to add another lane, so you’ll have duel lefts, duel rights and a through lane, ” said Rodi.
Correct : “They are going to add another lane, so you’ll have dual lefts, dual rights and a through lane,” said Rodi.
Incorrect: My ideal life would contain duel residences in SF and Palo Alto.
Correct : My ideal life would contain dual residences in SF and Palo Alto.
Incorrect: Duel ownership is severely limiting productivity as neither owner nor tenants invest in the land.
Correct : Dual ownership is severely limiting productivity as neither owner nor tenants invest in the land.
Incorrect: Jaguars beat Tigers in hard-fought dual
Correct : Jaguars beat Tigers in hard-fought duel
Incorrect: I still gave my all in our sword fighting duals.
Correct : I still gave my all in our sword fighting duels.
Incorrect: [She’s] the wife of a former Cuban Senator, who likes fighting duals.
Correct : [She’s] the wife of a former Cuban Senator, who likes fighting duels.
If you mean double, use dual. If you mean a fight or a contest between two participants, use duel.
To think for the last 40+ years I always thought that a Dual Carriageway in the UK meant two lanes in each direction. Never thought about the existence of a strip in between. More than 2 lanes and it is a Motorway. I would have to translate the term Dual Carriage way in the US to four lane highway. Turns out I was uninformed all these years.
I grew up in Brooklyn NY 50 years ago, and there were not a lot of trucks there, by which I mean pickup trucks and privately-owned smaller trucks. When I moved to Florida (which had more rural-ish areas, at least when I moved here 25 years ago), there were trucks that had 2 wheels (tires) in front and 4 in back (2 on each side). I paid no attention to it in the sense that it didn’t occur to me that there was a name for that tire arrangement. I had a friend who kept talking about his “dooley” (as I imagined it was spelled). I was quite surprised years later to see the word “dually,” referring to trucks with 2 tires on each side.