1. the time by which something must be finished, submitted, etc. 2. (formerly) a boundary around a military prison beyond which a prisoner could not venture without risk of being shot by the guards.
While it's important to talk with your doctor about the cause of your slurred speech, slurred speech caused by anxiety is not dangerous. It's not a sign that you have something else coming, or that your brain will somehow be inefficient for handling life tasks in the future.
Slurred speech is an example of an anxiety symptom that can be incredibly frightening. But it's common with those suffering from anxiety attacks, and in most cases it says nothing about the health of your brain. Anxiety attacks can cause a host of issues that may lead to slurred speech.