1. the act or process of registering or signing up as a member, student, or participant in a school, program, or organization
2. the total number of people registered or admitted to a school, program, or organization at a given time

Examples

• Enrollment for the fall semester begins next Monday.
• The university's enrollment increased by 15% this year.
• Early enrollment in the health insurance plan saves you money.
• Student enrollment peaked in the 1990s.
• She completed her enrollment form online.
• The school's total enrollment is over 2,000 students.
• Enrollment in advanced math classes is optional.
• The deadline for enrollment is August 31st.