Anxiety (noun)

1. A feeling of worry, nervousness, or unease about something with an uncertain outcome.
2. A feeling of unease, such as worry or fear, that can be mild or severe.
3. A condition in which a person feels agitated, restless, or worried, especially in the absence of a clear reason.

Origin:

Late middle english: from old french anxiete, from latin anxietas, from anxius (see anxious).

Examples:

1. She felt a knot of anxiety in her stomach as she waited for the results.
2. He struggled with anxiety and depression for many years.
3. The patient has been diagnosed with Generalized Anxiety Disorder.
4. The interview made her feel anxious and she couldn't focus on the questions.
5. The anxiety of waiting for the test results was overwhelming.