a bad excuse for

transitive verb excused, excusing

1. to try to free (a person) of blame; seek to exonerate
2. to try to minimize or pardon (a fault); apologize or give reasons for
3. to consider (an offense or fault) as not important; overlook; pardon: excuse my rudeness
4. to release from an obligation, duty, promise, etc.
5. to permit to leave
6. to serve as an explanation or justification for; justify; exculpate; absolve: a selfish act that nothing will excuse

noun

1. a plea in defense of or explanation for some action or behavior; apology
2. a release from obligation, duty, etc.
3. something that excuses; extenuating or justifying factor
4. a pretended reason for conduct; pretext