| Idiom | Meaning | Example | 
| odd one | 
(See the odd one)
 | 
 | 
| odds and ends | 
small pieces that are not used, tie up loose ends
 | 
When you build the fence, save the odds and ends to make toys.
 | 
| odds-on favorite | 
(See the odds-on favorite)
 | 
 | 
| of course you can | 
you can do it; yes, you can
 | 
"I can't read this fat book." "Of course you can, Johnny."
 | 
| of the lot | 
of the group, of the bunch
 | 
This rug is the best of the lot. It's nicer than the others.
 | 
| of two minds | 
having two opinions, mixed feelings
 | 
Speaking of abortion, I'm of two minds: pro choice and pro life.
 | 
| off | 
sour, spoiled
 | 
The cream tastes a bit off. I think we should buy fresh cream.
 | 
| off-beat | 
different, unusual
 | 
His condo has an off-beat design. There's a shower in the kitchen.
 | 
| off color | 
bad, dirty, impolite
 | 
His wife gets so embarrassed when he tells an off-color joke.
 | 
| off key (music) | 
not at the right pitch, not in tune
 | 
He has a beautiful voice, but wasn't he singing a bit off key?
 |