What does "ail" mean?

Ail: Note: It is never used to express a specific disease. We do not say, a fever ails him; but, something ails him.

Additional senses

  1. 2.To be affected with pain or uneasiness of any sort; to be ill or indisposed or in trouble. When he ails ever so little . . . he is so peevish. Richardson.
  2. 3.Indisposition or morbid affection. Pope.

Sources