* Miss: To fail to notice or understand.
* Overlook: To fail to notice something, often due to carelessness.
* Misinterpret: To understand something incorrectly.
* Confuse: To fail to distinguish between things.
* Ignore: To pay no attention to.
* Neglect: To fail to give proper attention to.
* Oblivious: Unaware of something.
* Indiscriminate: Making no distinction.
* Unclear: Difficult to understand or perceive.
* Vague: Not clearly defined or expressed.
The best antonym depends on the specific context in which "discern" is used.