简朴的英文：
simple and unadorned
plain

The hotel room was somewhat spartan.
这家旅店的客房很简朴。

They live simple and happy lives.
他们过着简朴而幸福的生活。

Despite being filthy rich, Mr. C is still leading his life in a frugal way.
尽管 C 先生很富有，他仍然过著简朴的生活。

It is ludicrous to call a simple split-level house a mansion.
把一座简朴的错层式的房子叫做大厦真太可笑了

An unostentatious office
简朴的办公室

They live very simply.
他们生活得很简朴。

The church was austere and simple.
教堂的布置很简朴。

Preferred plain living.
偏爱简朴的生活

He is leading a very simple life.
他过着十分简朴的生活。

He advocates plain living.
他提倡过简朴的生活。

Simple pushbuttons for simple functions are good.
对于简单的功能来说，简单的按钮就足够了。

This book has a simple premise:
本书有一个简单的前提：

He is Spaniard pure and simple
他是一个纯血统的西班牙人

(of style,appearance, clothing,etc)unadorned;simple
(指风格、外貌、衣物等)无装饰的,简单的

What’s missing from an unadorned, virtual manual affordance is any idea of what function it performs.
一个未加修饰的虚拟手动启示缺少其所执行的功能信息。

"Loveliness, needs not the foreign aid of ornament, But is when unadorn'd, adorn'd the most. 　-- James Thompson"
可爱,并不需要外来的装饰,天然的可爱远比雕饰的更可爱--J·汤普森

plain stupidity
十足的笨蛋

This is plain on the face of the facts.
这一点，从事实的表面就可以清楚地看出来。

the diamond was in a plain gold mount.
这个钻石嵌在一个金底板上。