Outer
Part of speech: adjective
Definition: Outside; external. Farther from the centre of the inside.
Part of speech: noun
Definition: An outer part. (wholesale trade) the smallest single unit normally sold to retailers, usually equal to one retail display box. Someone who admits to something publicly. Someone who outs another.
Example sentence: Here we have the Schengen agreement, and the truth is that for years we trusted each other and set border controls on the outer borders of the European Union. And as was the case with the economic and monetary union, with this step, regarding the management of the Schengen area, we did not go all the way in terms of political solutions.
Outmost
Part of speech: adjective
Definition: Superlative form of out.Farthest outside; as far from the center or inside as possible.