1. in a way that is required by law, rule, or duty; compulsorily

Examples

• All students must obligatorily attend the safety briefing.
• The form must be obligatorily signed by a parent or guardian.
• Employees are obligatorily required to wear protective equipment.
• The course includes obligatorily assigned readings.
• Taxes are obligatorily deducted from each paycheck.
• The meeting is obligatorily scheduled for all department heads.