The Collaborative International Dictionary of English v.0.48:

Toothache \Tooth"ache`\, n. (Med.)
   Pain in a tooth or in the teeth; odontalgia.
   [1913 Webster]

   Toothache grass (Bot.), a kind of grass (Ctenium
      Americanum) having a very pungent taste.

   Toothache tree. (Bot.)
   (a) The prickly ash.
   (b) A shrub of the genus Aralia (Aralia spinosa).
       [1913 Webster]