| Idiom | Meaning | Example | 
| open to question | 
not clearly correct, debatable
 | 
Your decision to allow liquor at the party is open to question.
 | 
| open up | 
talk openly, express feelings
 | 
When we become friends, I'll open up with you - I'll share.
 | 
| open up a big can of whoop-ass | 
punish, discipline, whup your ass
 | 
If you don't stop jumping on the couch, I am going to open up 
a big can of whoop-ass!
 | 
| other fish to fry | 
(See bigger fish to fry)
 | 
 | 
| ounce of prevention | 
(See an ounce of prevention)
 | 
 | 
| out and out | 
bold, not hidden, a bare-faced lie
 | 
The advertisement was an out-and-out lie. It contained no truth.
 | 
| out cold | 
unconscious,  knocked out
 | 
Liam is out cold. A baseball hit him on the side of the head.
 | 
| out for blood | 
trying to defeat or hurt, seeking revenge
 | 
The Jets are out for blood tonight because they lost 7-0 last night.
 | 
| out in left field | 
not logical or sensible, all wet
 | 
Don't listen to his advice. He's out in left field.
 | 
| out in the cold | 
not included in a group, not invited
 | 
He was left out in the cold because of his religious beliefs.
 |