From BiblePortal Wikipedia

King James Dictionary [1]

BAN'ISHMENT, n. The act of a prince or government, compelling a citizen to leave his country, either for a limited time or forever, as for some crime.

2. A voluntary forsaking of one's country upon oath, called abjuration. This practice has now ceased in G.Britain. 3. The state of being banished exile. 4. The act of driving away or dispelling as the banishment of care from the mind.

Hastings' Dictionary of the Bible [2]

Banishment . See Crimes and Punishments.

Webster's Dictionary [3]

(n.) The act of banishing, or the state of being banished.