Conterminously is a complex word that means "having the same boundaries or borders." There are several synonyms that can be used in place of conterminously, including "adjacent," "contiguous," "coterminous," and "neighboring." Each of these words offers a slightly different meaning. For example, adjacent means "next to," while contiguous means "touching." Coterminous means "having the same boundaries or limits," and neighboring means "nearby." Depending on the context, any of these words can be used in exchange for conterminously to convey the same idea of things being next to or touching each other.