Or else
Or suffer the consequences.The teacher told the students to be quiet or else.
The opposite sex
The opposite sex to someone (either male or female).The math classes were divided so that nobody had to study with a member of the opposite sex.
An opening gambit
An opening statement etc. to help give one an advantage in bargaining etc..The union made several concessions in their opening gambit while... Read more →
Open with (something)
To start with something.The convention opened with a speech from the president of our company.
Open up to (someone)
To talk frankly or truthfully to someone.I always open up to my friend when I meet her.
Open up on (someone or something)
To attack someone or something, to fire a gun or other weapon at someone or something.The man with the gun opened up on the people on the bus.
Open up a can of worms
To create unnecessary complications.The dispute with our competitor opened up a can of worms about how to market our product.
Open to (something)
To be willing to learn or hear about new ideas or suggestions.Our principal is open to new ideas about how to meet the needs of the students.
Open the door to (something)
To permit/allow something to become a possibility.The new sports center opened the door to many possibilities for getting the students involved... Read more →
Open (something) up open up (something)
To start the use of something such as land or a building.The government is planning to open more land up to farming.