Tardiness is the habit or state of being late. When a student arrives after the bell rings, that's tardiness. When someone consistently shows up ten minutes after they promised, they're showing a pattern of tardiness.

The word often implies a repeated problem or a personal tendency. A teacher might excuse one late arrival but become concerned about ongoing tardiness. Schools track tardiness because arriving late disrupts class.

Tardiness affects schedules and relationships. When you're tardy to a friend's birthday party, you might miss the games or the cake cutting. When someone's tardiness delays a team project meeting, everyone else has to wait around with nothing to do.

Occasional lateness happens to everyone, but making tardiness a habit can affect your reputation because others may find it harder to count on you.