alibi

Noun

• a defense of some offensive behavior or some failure to keep a promise etc.
  • he kept finding excuses to stay
    
  • every day he had a new alibi for not getting a job
    
  • his transparent self-justification was unacceptable
    

• (law) a defense by an accused person purporting to show that he or she could not have committed the crime in question

Verb

• exonerate by means of an alibi

Related words

• Synonyms: 
  excuse , exculpation , self-justification