adjective / noun
outer
OUT-er/ˈaʊtər/
Situated toward or on the outside.
The child peels away the onion's outer layer, leaving the inner layers intact.

Etymology
Outer combines out with a comparative ending, literally meaning “farther out.” It locates something farther from the inside or center, hence on or toward the outside.
In context
The epidermis is the outer layer we can see.
The egg's rugged outer shell called the chorion
More examples
- We sit near the outer edge of the crowd.
- The jacket has a waterproof outer and a soft lining.
- A cardboard outer holds the smaller boxes together.
Forms
outer · outers · outermost
outerwear noun — Clothing worn over other garments outdoors.