Wordnet 3.0
NOUN (2)
1. 
 a person who creates classifications; 
2. 
 a word or morpheme used in some languages in certain contexts (such as counting) to indicate the semantic class to which the counted item belongs; 
The Collaborative International Dictionary of English v.0.48:
Classifier \Clas"si*fi`er\, n.
   One who classifies.
   [1913 Webster]
WordNet (r) 3.0 (2006):
classifier
    n 1: a person who creates classifications
    2: a word or morpheme used in some languages in certain contexts
       (such as counting) to indicate the semantic class to which
       the counted item belongs