unfathomable

英 [ʌn'fæð(ə)məb(ə)l] 美[ʌn'fæðəməbl]

• adj. 深不可测的；无底的；莫测高深的

1. of depth; not capable of being sounded or measured

2. so deep as to be unmeasurable;

"the abyssal depths of the ocean"

3. impossible to come to understand