The Collaborative International Dictionary of English v.0.48:

Ache \Ache\, n. [OE. ache, AS. [ae]ce, ece, fr. acan to ache.
   See Ache, v. i.]
   Continued pain, as distinguished from sudden twinges, or
   spasmodic pain. "Such an ache in my bones." --Shak.
   [1913 Webster]

   Note: Often used in composition, as, a headache, an earache,
         a toothache.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ache \Ache\, v. i. [imp. & p. p. Ached; p. pr. & vb. n.
   Aching.] [OE. aken, AS. acan, both strong verbs, AS. acan,
   imp. [=o]c, p. p. acen, to ache; perh. orig. to drive, and
   akin to agent.]
   To suffer pain; to have, or be in, pain, or in continued
   pain; to be distressed. "My old bones ache." --Shak.
   [1913 Webster]

         The sins that in your conscience ache.   --Keble.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ach \Ach\, Ache \Ache\, n. [F. ache, L. apium parsley.]
   A name given to several species of plants; as, smallage, wild
   celery, parsley. [Obs.] --Holland.
   [1913 Webster] Achaean

WordNet (r) 3.0 (2006):

ache
    n 1: a dull persistent (usually moderately intense) pain [syn:
         ache, aching]
    v 1: feel physical pain; "Were you hurting after the accident?"
         [syn: hurt, ache, suffer]
    2: have a desire for something or someone who is not present;
       "She ached for a cigarette"; "I am pining for my lover" [syn:
       ache, yearn, yen, pine, languish]
    3: be the source of pain [syn: ache, smart, hurt]