cryptic

/ˈkrɪp.tɪk/
with a meaning that is hidden or not easily understood 含义隐晦的；晦涩难懂的 SYN mysterious
a cryptic message/remark/smile
令人困惑的信息／话语／微笑
a cryptic crossword clue
扑朔迷离的纵横字谜线索