The numbers 1, 3, 5, and 35 are all odd numbers — they can't be divided by two. They are not even. Also, things that are weird or strange are called odd.
This word covers things that are slightly off-kilter, like odd numbers. You can use odd for a single thing that belongs in a pair, like an odd sock or odd mitten. If someone wants you to do odd jobs, that could mean almost anything: odd jobs are random and unpredictable jobs that could come up. When you describe a person as odd, or that they’re exhibiting odd behavior, it means they're peculiar and out of the ordinary.
adj not used up
adj not easily explained
not usual or common or ordinary