不可捉摸
Pinyin: bù kě zhuō mo
Definition: To be difficult to understand or predict; unpredictable.
Etymology: From the Tang dynasty poet Bai Juyi's poem "On a Windy Night" where he writes about feelings that are hard to grasp and elusive like the wind at night.
Example Sentence: The stock market is often described as being full of variables and thus, its movements can be considered as 'unpredictable' or 'not easily grasped by human minds' (不可捉摸).
