Describes landscapes so beautiful that they can't be described in words. Comes from the Adirondacks, a mountain range in upper New York State. Pronounced "a-dih-ron-DACK-you-ler".
Marty: Yo, Dean, get a look at this black spruce bog---it's adirondackular!!!
Dean: Yeah, dis is awesome man! It's like Yoda's planet!
Marty: Dean, you sure know how to pick the best boreal hikes!