hieroglyphic

这份古代手稿上的符号太复杂了，对我来说就像天书一样难懂。

The symbols on this ancient manuscript are so complex that they appear ___hieroglyphic to me.

工程师的电路图在营销团队眼中完全像天书一样。

The engineer's circuit diagram looked completely ___hieroglyphic to the marketing team.

对新来的实习生来说，公司内部的缩写简直就是天书。

To the new intern, the company's internal abbreviations were practically ___hieroglyphic.