How do you spell Ailing

Available Definitions:
1)  v. t. - To affect with pain or uneasiness, either physical or mental; to trouble; to be the matter with; -- used to express some uneasiness or affection, whose cause is unknown; as, what ails the man? I know not what ails him.
2)  v. i. - To be affected with pain or uneasiness of any sort; to be ill or indisposed or in trouble.
3)  n. - Indisposition or morbid affection.