不気味の谷

From 不気味(ぶきみ) (bukimi, “eerie, uncanny”, of Middle Chinese origin, literally “bad taste and smell”) + の (no, genitive particle) + 谷(たに) (tani, “valley”).

Coined by Masahiro Mori in 1970, to describe a dip in the likeability of a humanoid robot in relation to its resemblance to the human face to the point where it becomes “uncanny”, before picking up again as the human resemblance nears perfection, thus forming a “valley”.

不(ぶ)気(き)味(み)の谷(たに) • (bukimi no tani) 

1. (robotics, psychology) uncanny valley