DynamicSupervisor.terminate_child

You're seeing just the function terminate_child, go back to DynamicSupervisor module for more information.
Link to this function

terminate_child(supervisor, pid)

View Source (since 1.6.0)

Specs

terminate_child(Supervisor.supervisor(), pid()) :: :ok | {:error, :not_found}

Terminates the given child identified by pid.

If successful, this function returns :ok. If there is no process with the given PID, this function returns {:error, :not_found}.