fathomless

1. ADJ Something that is fathomless cannot be measured or understood because it gives the impression of being very deep, mysterious, or complicated. 深不可測的; 不能理解的

...the fathomless space of the universe. ...深不可測的宇宙空間。

The silence was fathomless and overwhelming. 這樣的沉靜不能測透、侵襲著一切。