Apocope

from WordNet (r) 3.0 (2006)

apocope
    n 1: abbreviation of a word by omitting the final sound or
         sounds; "the British get `pud' from `pudding' by apocope"

from The Collaborative International Dictionary of English v.0.48

Apocope \A*poc"o*pe\, n. [L., fr. Gr. ? a cutting off, fr. ? to
   cut off; ? from + ? to cut.]
   1. The cutting off, or omission, of the last letter,
      syllable, or part of a word.
      [1913 Webster]

   2. (Med.) A cutting off; abscission.
      [1913 Webster] Apocrisiary