odd

The word “odd” means strange, unusual, or not what you would expect. In plain terms, strange, or (in math) not divisible by two, or (of items) unmatched/left over.

“Odd” is pronounced od (/ɑd/ in IPA).

Here is “odd” used in a sentence: “There was an odd smell coming from the basement.”

“Odd” is an adjective.

The word “odd” comes from Old Norse. From Old Norse oddi, meaning "point" or "triangle" — an object that stuck out on its own rather than pairing neatly with another, which is how it came to mean "leftover" or "unmatched".

“Odd” is a fairly common word in modern English, usually learned at around the B2 level.

“Odd” has 4 distinct senses listed in this dictionary. The most common is: strange, unusual, or not what you would expect.

In mathematics the two are opposites: an even number can be divided exactly by two, while an odd number cannot, always leaving a remainder of one. Away from numbers, odd has a second everyday meaning of strange or unusual, and it is this sense that most often causes confusion with words like weird.

You might call it odd if a shop is closed on a busy afternoon with no notice, or if a friend suddenly starts behaving out of character. The word suits anything unexpected, puzzling, or slightly out of place, from a strange noise in the night to an unusual choice of clothing.

Not strongly. Odd mostly signals that something is unusual or unexpected rather than clearly bad, and it can even sound gently amusing or intriguing. Tone and context decide: calling an idea odd is mild, but describing a person as odd can feel a little unkind depending on how it is said.

The two are close and often interchangeable. Odd tends to suggest something mildly unusual or not quite as expected, while strange can feel a little stronger, hinting at something harder to explain or even unsettling. In casual speech, though, most people use them to mean much the same thing.