WordWeb Online

1. An expression of regret at having caused trouble for someone
   "he wrote a letter of apology to the hostess"
    
2. A formal written defence of something you believe in strongly
   - apologia
    
3. A poor example
   "it was an apology for a meal";
   - excuse

Derived forms: apologies

Type of: account, acknowledgement, acknowledgment, defence [Brit, Cdn], defense [US], example, exemplum, illustration, instance, representative, vindication

Encyclopedia: Apology