のっぺらぼう

noun which may take the genitive case particle 'no', na-adjective, noun

unchanging; monotonous; expressionless

Used for things that lack variation or character, such as a monotonous landscape, an expressionless face, or a dull routine.

• 彼かれののっぺら坊ぼうな表ひょう情じょうからは何なにも読よみ取とれなかった。

  I couldn't read anything from his expressionless face.

• この辺あたりはのっぺら坊ぼうな田でん園えん風ふう景けいが続つづいている。

  Around here, a monotonous rural landscape stretches on.

noun

noppera-bō; faceless ghost

In Japanese folklore, a yōkai that appears as a human but has a completely smooth, featureless face. Often used to scare people.

• のっぺら坊ぼうは、顔かおのない妖よう怪かいとして知しられている。

  The noppera-bō is known as a faceless yōkai.