(a) As used in this article, the term "contiguous area" means, at the time the annexation procedures are initiated, any area that meets the following conditions:

"contiguous area" means any area of which at least one-eighth of the aggregate external boundary, at the time annexation procedures are initiated, directly abuts the municipal boundary. Any area shall also be a "contiguous area" if at least one-eighth of its [...]

"Contiguous area" means any area which, at the time annexation procedures are initiated, either abuts directly on the municipal boundary or is separated from the municipal boundary by a street or street right of way, a creek or river, the right of way of a railroad [...]

"Contiguous area" means any unincorporated area which, on or after January 1, 1999, had an aggregate external boundary directly abutting a municipal boundary. Any area shall be considered "contiguous" if the aggregate external boundary would directly abut the [...]