The Collaborative International Dictionary of English v.0.48:

Retrieval \Re*triev"al\, n.
   The act retrieving.
   [1913 Webster]

WordNet (r) 3.0 (2006):

retrieval
    n 1: (computer science) the operation of accessing information
         from the computer's memory
    2: the cognitive operation of accessing information in memory;
       "my retrieval of people's names is very poor"
    3: the act of regaining or saving something lost (or in danger
       of becoming lost) [syn: recovery, retrieval]