| OP | a vacant or unobstructed space |
|---|---|
| OP | an aperture or hole opening into a bodily cavity |
| OP | a possible alternative |
| OP | the initial part of the introduction |
| OP | the first performance (as of a theatrical production) |
| OP | a ceremony accompanying the start of some enterprise |
| OP | an open or empty space in or between things |
| OP | opportunity especially for employment or promotion |
| OP | first or beginning |
| OP | the first line of a piece of writing (as a newspaper story) |
| OP | the first of a series of actions |
| OP | the first performance (as of a theatrical production) |