1. lacking self-control or the ability to behave in a controlled and calm way
2. not following rules, training, or proper methods

Examples

• The undisciplined children ran wild through the store.
• His undisciplined spending habits led to serious debt.
• The team’s undisciplined play cost them the championship.
• She struggled with undisciplined eating patterns.
• The undisciplined soldiers broke formation during the drill.
• His undisciplined approach to studying hurt his grades.
• The undisciplined crowd pushed toward the stage.