As used in this act:

  (a) “Municipality” means a city, village, or township.

  (b) “Participating” means, with respect to a municipality, that the municipality is a member of a joint planning commission.

  (c) “Registered elector of the municipality” means a registered elector residing in the municipality or, if the municipality is a township, a registered elector residing in the portion of the township outside the limits of any village.