高深莫測 gāo shēn mò cè

DEFINITIONS

  1. profound mystery

CHARACTERS

高 gāo
HSK 1
high, tall; lofty, elevated
深 shēn
HSK 4
deep; depth; far; very, extreme
莫 mò
HSK 6
do not, is not, can not; negative
測 cè measure, estimate, conjecture