adj. 1
Differing from what is usual, ordinary or expected.
She slept in, which was very odd.
adj. 2
Without a corresponding mate in a pair or set; unmatched; (of a pair or set) mismatched.
My cat Fluffy has odd eyes: one blue and one brown.
adj. 3
Differing from what is usual, ordinary or expected. Peculiar, singular and strange in looks or character; eccentric, bizarre.
adj. 4
Left over, remaining after the rest have been paired or grouped.

Related words

Word family: oddball oddish oddity oddling oddly oddment oddness odd-pinnate
Phrases: odd duck odd fish odd man out odd bod odd lot odd bird odd job odd man wins

Choose the right word

Odd or Singular?

Odd is unmated, as an odd shoe, and so uneven, as an odd number. What is singular is odd, but what is odd may not be singular; as, a drawerful of odd gloves.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

strange Press the red button if something strange happens.
unusual The study by Meyer and his colleagues was unusual.
curious He is curious about how she will receive the news.
peculiar The custom of bowing is peculiar to the islanders.
plus One crook plus one crook is equal to zero crooks.
assorted The butcher shop sells assorted cuts of meat.

Popularity over time

Word	1850 → 2019	Trend
odd		rising
strange		rising
unusual		steady
curious		rising
peculiar		falling
plus		falling

Use in printed books, per decade from 1850 to 2019.

By length

4 letters: over², left¹, plus¹, rare¹
5 letters: funny², extra², weird¹, kooky²
6 letters: single², uneven³, quaint¹
7 letters: strange¹, unusual⁴, curious³, bizarre², unmated
8 letters: uncommon³, peculiar³, singular³, abnormal³, assorted³, freakish, unpaired
9 letters: different³, remaining³, eccentric³, unmatched²
10 letters: ridiculous⁴, occasional⁴, outlandish³, mismatched², unexpended
13 letters: extraordinary⁶
14 letters: unconventional⁵

The small number after each word is its number of syllables (over² = 2 syllables).