For xinetd service definition, which config option will disable the service?

Answer: disable

Explanation/Reference:
From the man pages:
xinetd.conf is the configuration file that determines the services provided by xinetd.
disable   this is boolean "yes" or "no". This will result in the service being disabled and not starting.

Example:
service myorg_server
{
  disable=no
  type=INTERNAL
  socket_type=stream
  protocol=tcp
  wait=no
  user=root
  server=/usr/etc/my_server_exec
}