1. the act or process of registering or signing up as a member, student, or participant in a program, course, or organization
Usage: British spelling; American English typically uses 'enrollment'; commonly used in educational contexts
2. the total number of people registered or admitted to a school, program, or organization at a given time
Usage: often used as a count noun in statistical or administrative contexts

Examples

• Enrolment for the spring semester begins next Monday.
• The university saw a 15% increase in enrolment this year.
• Students must complete their enrolment before the deadline to secure a place.
• Early enrolment in the course guarantees a spot in the class.
• The school's enrolment has grown steadily over the past five years.
• Online enrolment makes it easier for students to register from home.