simple

Apart from anything else; without additions or modifications.

“the simple passage of time was enough”

“the simple truth”

Exhibiting childlike simplicity and credulity.

(botany) of leaf shapes; of leaves having no divisions or subdivisions.

Easy and not involved or complicated.

“a simple game”

Lacking mental capacity and subtlety.

Having few parts; not complex or complicated or involved.

“a simple problem”

“simple mechanisms”

Unornamented.

“a simple country schoolhouse”

“her black dress--simple to austerity”

A person lacking intelligence or common sense.

Any herbaceous plant having medicinal properties.