Ail \Ail\ ([=a]l), v. t. [imp. & p. p. {Ailed} ([=a]ld); p. pr.
& vb. n. {Ailing}.] [OE. eilen, ailen, AS. eglan to trouble,
pain; akin to Goth. us-agljan to distress, agls troublesome,
irksome, aglo, aglitha, pain, and prob. to E. awe. [root]3.]
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.