tiān​rán​dāi

space cadet

天然呆 tiān​rán​dāi
space cadet
(loanword from Japanese 'tennen boke') a character archetype describing someone who is naturally muddleheaded, slow to react, and innocently ditzy. It refers to a person who makes silly mistakes or acts in a foolish way without realizing it, often creating a humorous or cute effect.