OP

go co-op

Typically said of an apartment building that has become a cooperative (or "co-op")—a building in which residents do not own property but rather own shares in the corporation that owns the building. I can't believe that our building is going co-op—I might need to move.
See also: go

OP

1. slang An initialism for "other people," referring to a cigarette given to one by someone whom one asked for it. He stumbled out of the bar going around to the people outside looking for OPs.
2. slang By extension, a person who asks someone for a cigarette. Cynthia doesn't smoke for the most part, but whenever we go out drinking she turns into such an OP!
3. slang An initialism of "overpowered," referring to a character, weapon, move, or other aspect of the game that is unfairly strong in comparison to the rest of the game. Beating the side quest nets you a mystical sword that is so OP that you basically can't be beaten from that point on. The new character they added to the fighting game has a very cool design, but she is totally OP. Unless the developers nerf her moves, I doubt she'll be allowed in competitive play.

op-ed piece

In journalism, an article that expresses a writer's viewpoint or opinion, rather than reporting factual information. "Op-ed" stands for "opposite" the "editorial page." I think our readers would really be interested in hearing the viewpoint of someone who only recently moved to the area. How would you like to write an op-ed piece for us? Why is there so much editorializing in this article? Oh, because it's an op-ed piece.
See also: piece

photo op

A shortening of "photo(graph) opportunity," literally, an ideal chance to take photographs, especially of someone famous. The actors all got together for a photo op with fans at the convention. The CEO agreed to a rare photo op for the press.
See also: OP, photo
Farlex Dictionary of Idioms.

photo op(portunity)

a time or event designed for taking pictures of a celebrity. All the photographers raced toward a photo op with the president.
See also: OP, photo
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

OP’s

(ˈoˈpiz)
n. other people’s cigarettes; begged or borrowed cigarettes. (Initialism.) My favorite kind of cigarettes is OP’s. They’re the cheapest, too.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions

photo op

A chance for a photograph, often for publicity purposes. The “op” here is short for “opportunity.” Deborah Eisenberg used it in her story, “Under the 82nd Airborne”: “‘Relax,’ Lewis said. ‘There’s no one here for them to fight with—this is a photo op.’” See also sound bite.
See also: OP, photo
The Dictionary of Clichés by Christine Ammer
See also:
  • go co-op
  • build (something) out over (something)
  • build (something) over (something)
  • build out over
  • built on sand
  • room for rent
  • blow up
  • blowing up
  • blown up
  • brown out