| OP | having influence or producing an effect |
|---|---|
| OP | conditioning in which an operant response is brought under stimulus control by virtue of presenting reinforcement contingent upon the occurrence of the operant response |
| OP | perform surgery on |
| OP | happen |
| OP | perform a movement in military or naval tactics in order to secure an advantage in attack or defense |
| OP | handle and cause to function |
| OP | keep engaged |
| OP | perform as expected when applied |
| OP | direct or control |
| OP | perform surgery on |
| OP | of or relating to or characteristic of opera |
| OP | singer of lead role in an opera |