The Collaborative International Dictionary of English v.0.48:

Detrition \De*tri"tion\, n. [LL. detritio. See Detriment.]
   A wearing off or away.
   [1913 Webster]

         Phonograms which by process long-continued detrition
         have reached a step of extreme simplicity. --I. Taylor
                                                  (The
                                                  Alphabet).
   [1913 Webster]

WordNet (r) 3.0 (2006):

detrition
    n 1: erosion by friction [syn: abrasion, attrition,
         corrasion, detrition]
    2: the wearing down of rock particles by friction due to water
       or wind or ice [syn: grinding, abrasion, attrition,
       detrition]
    3: effort expended in moving one object over another with
       pressure [syn: friction, detrition, rubbing]