The Collaborative International Dictionary of English v.0.48:

Dentifrice \Den"ti*frice\, n. [L. dentifricium; dens, dentis,
   tooth + fricare to rub: cf. F. dentifrice. See Tooth, and
   Friction.]
   A powder or other substance to be used in cleaning the teeth;
   tooth powder.
   [1913 Webster]

WordNet (r) 3.0 (2006):

dentifrice
    n 1: a substance for cleaning the teeth; applied with a
         toothbrush

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "dentifrice":
   abstergent, cathartic, cleaner, cleaning agent, cleaning solvent,
   cleanser, cleansing cream, cold cream, cream, depurant, detergent,
   diuretic, emetic, enema, gargle, holystone, lotion, mouthwash,
   nauseant, pumice stone, purgative, purge, purifier, rinse, shampoo,
   soap, solvent, synthetic detergent, tooth powder, toothpaste,
   wash