The Collaborative International Dictionary of English v.0.48:

Adjuster \Ad*just"er\, n.
   1. One who, or that which, adjusts.
      [1913 Webster]

   2. an insurance agent who examines claims against personal or
      property damage insurance policies and makes estimates and
      recommendations regarding the amount which should be paid
      to the policyholder.
      [PJC] Adjusting plane

WordNet (r) 3.0 (2006):

adjuster
    n 1: one who investigates insurance claims or claims for damages
         and recommends an effective settlement [syn: adjuster,
         adjustor, claims adjuster, claims adjustor, claim
         agent]