anxiety

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A state of uneasiness and apprehension, as about future uncertainties.
2. n. A cause of anxiety: For some people, air travel is a real anxiety.
3. n. Psychiatry A state of apprehension, uncertainty, and fear resulting from the anticipation of a realistic or fantasized threatening event or situation, often impairing physical and psychological functioning.
4. n. Eager, often agitated desire: my anxiety to make a good impression.

Century Dictionary and Cyclopedia

1. n. The apprehension caused by danger, misfortune, or error; concern or solicitude respecting some event, future or uncertain; disturbance, uneasiness of mind, or care, occasioned by trouble.
2. n. In pathology, a state of restlessness and agitation, with general indisposition, and a distressing sense of oppression at the epigastrium. Synonyms Care, Concern, Solicitude, etc. (see care), foreboding, uneasiness, disquiet, inquietude, restlessness, apprehension, fear, misgiving, worry.

Wiktionary

1. n. An unpleasant state of mental uneasiness, nervousness, apprehension and obsession or concern about some uncertain event.
2. n. An uneasy or distressing desire (for something).
3. n. pathology A state of restlessness and agitation, often accompanied by a distressing sense of oppression or tightness in the stomach.

GNU Webster's 1913

1. n. Concern or solicitude respecting some thing or event, future or uncertain, which disturbs the mind, and keeps it in a state of painful uneasiness.
2. n. Eager desire.
3. n. (Med.) A state of restlessness and agitation, often with general indisposition and a distressing sense of oppression at the epigastrium.

WordNet 3.0

1. n. a vague unpleasant emotion that is experienced in anticipation of some (usually ill-defined) misfortune
2. n. (psychiatry) a relatively permanent state of worry and nervousness occurring in a variety of mental disorders, usually accompanied by compulsive behavior or attacks of panic