unfathomable
US
UK unfathomable adj: (impossible to measure)
SC 深不可测的 shēn bù kě cè de
SC 不可测量的 shēn bù kě cè de，bù kě cè liáng de
SC 无底的 shēn bù kě cè de，wú dǐ de
Many unusual creatures inhabit the unfathomable depths of the ocean.
unfathomable adj: figurative (impossible to comprehend)
SC 难以理解的 nán yǐ lǐ jiě de
SC 高深莫测的 nán yǐ lǐ jiě de ，gāo shēn mò cè de
For some unfathomable reason, Derek decided to go for a walk in the rain.