Furthest and Outer

Furthest adjective - Most distant from a center.

Outer and furthest are semantically related in outlying topic. In some cases you can use "Outer" instead an adjective "Furthest".

Outer adjective - Situated on the outside or farther out.

Furthest and outer are semantically related in outlying topic. You can use "Furthest" instead an adjective "Outer".