perplexity

n.

困惑；混乱；复杂；困难

复数：perplexities

1. She looked at us in perplexity.
   她茫然地看着我们。
2. He wrinkled up his forehead in perplexity.
   他困惑地皱起了眉头。
3. It's a problem of such perplexity that it was impossible to solve.
   那是个复杂得无法解决的问题。

From Complexity to Perplexity
Perplexity and Precision in the Diagnosis of Streptococcal Pharyngitis
The current taxonomy and perplexity of the genus Oryza (Poaceae)
Perplexity minimization for translation model domain adaptation in statistical machine translation
Trends in Complexity Studies: From Complexity to Perplexity
Method and system for reducing perplexity in speech recognition via caller identification
DNA amplification at 11q13 in human cancer: from complexity to perplexity.
Early diagenesis of organic matter in marine sediments: progress and perplexity
Investigating the relationship between language model perplexity and IR precision-recall measures
Apparatus and method for reducing speech recognition vocabulary perplexity and dynamically selecting acoustic models