| ER | (baseball) a failure of a defensive player to make an out when normal play would have sufficed |
|---|---|
| ER | inadvertent incorrectness |
| ER | departure from what is ethically acceptable |
| ER | a misconception resulting from incorrect information |
| ER | part of a statement that is not correct |
| ER | (computer science) the occurrence of an incorrect result produced by a computer |
| ER | (computer science) a coding system that incorporates extra parity bits in order to detect errors |
| ER | capable of making an error |
| ER | free from error |
| ER | artificial and inferior |
| ER | any of several related languages of the Celts in Ireland and Scotland |
| ER | United States author remembered for novels about poverty and degeneration (1903-1987) |