Ail v. t. [imp. & p. p. Ailed p. pr. & vb. n. Ailing.]  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.
     What aileth thee, Hagar?   --Gen. xxi. 17.
  Note: ☞ It is never used to express a specific disease. We do not say, a fever ails him; but, something ails him.
  ailing
       adj : somewhat ill or prone to illness; "my poor ailing
             grandmother"; "feeling a bit indisposed today"; "you
             look a little peaked"; "feeling poorly"; "a sickly
             child"; "is unwell and can't come to work" [syn: indisposed,
              peaked(p), poorly(p), sickly, unwell, under
             the weather]