tàn mì
to explore a mystery
to probe the unknown
guǐ mì
secretive
furtive
surreptitious
shén mì mò cè
mystery
unfathomable
enigmatic
mì chuán
secretly transmitted
esoteric lore
mì ér bù xuān
to withhold information
to keep sth secret
mì cáng
hidden
a hidden treasure (often a Buddhist relic)
to keep secret