A more thorough explanation:

Definition: A councilor is a person who serves on a council, especially at the local level. It can also be spelled as councillor.

Example: John was elected as a councilor for his town's local council.

Example: The councilor suggested that the town should invest in more parks and recreational facilities for the community.

These examples illustrate how a councilor is someone who is elected or appointed to serve on a council, and their role is to represent the interests of their community and make decisions that benefit the local area.