simple

apart from anything else; without additions or modifications

“the simple passage of time was enough”

exhibiting childlike simplicity and credulity

a person lacking intelligence or common sense

of leaf shapes; of leaves having no divisions or subdivisions

easy and not involved or complicated

“a simple game”

lacking mental capacity and subtlety

any herbaceous plant having medicinal properties

having few parts; not complex or complicated or involved

“a simple problem”

unornamented

“a simple country schoolhouse”