perplexity

perplex +‎ -ity, from Middle French perplexité or post-classical Latin perplexitas ‘entanglement’, from perplexus.

• (UK) IPA^(key): /pəˈplɛksɪti/
• (US) IPA^(key): /pəɹˈplɛksədi/

perplexity (countable and uncountable, plural perplexities)

1. The state or quality of being perplexed; puzzled or confused.
2. Something that perplexes.
   • 1942, Rebecca West, Black Lamb and Grey Falcon (Canongate 2006), page 149:

     The Emperor, who was by then a focus of unresolvable perplexities, stood providing a strongly contrary appearance.

3. In information theory, a measurement of how well a probability distribution or model predicts a sample.