Alibi means a defence where an accuse alleges that at the time when the offence with which he is charges was committed, he was elsewhere.

Hello Linky, Alibi: Has 2 meanings: One is more formal and used often in law cases as a defend by an accused person to show that he could not have committed the crime in question. In a less formal way it could be used as a defense or excuse for some failure to keep a promise: ' He came up with new alibis every day for not getting a job' Excuses could be used here as well ,but 'allibi' is more intended to turn away a blame or punishment. Excuse: to justify one's conduct or behavior by reasoning. 'That isn't a good excuse for coming late'. It could also mean: - to grant exemption or release to: 'Excuse me from this task'. - to overlook or be lenient with ,tolerate something or someone : ' He excused her foolish behavior'