Ail

v. t. [imp. & p. p. AILED; p. pr. & vb. n. AIL-ING.] [A. S. eglan, eglian, eltan, eglian, to feel pain, to trouble, me egleth, it grieves me, egle, sharp, troublesome, Goth. agls, troublesome, irksome, aglo, aglitha, pain, trouble.] To affect with pain or uneasiness, either physical or mental; to trouble; to be the matter with; to affect in any way;—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.

It is never used to express a specific disease. We never say, a fever ails him; but something ails him.