Unexcused (adjective)

Not freed from an obligation or penalty by means of an excuse; not having an excuse.

Origin:

From un- (not) + excused (freed from an obligation or penalty by means of an excuse).

Examples:

1. The absence was unexcused, so the student was given detention.
2. The tardiness was unexcused, so the employee was docked pay.
3. The mistake was unexcused, so the team lost the game.
4. The broken rule was unexcused, so the team was disqualified.
5. The absence from the meeting was unexcused, so the employee was not considered for promotion.