天然呆

tiānrándāi
  1. (loanword from Japanese "tennen boke") space cadet
  2. muddleheaded

CEDICT

loanword

Entry Composition

1 天然 tiānrán natural
=2 呆 dāi
  1. foolish; stupid
  2. expressionless; blank
  3. variant of 待 dāi
=2 呆 dāi
  1. foolish; stupid (variant of 呆 dāi)
  2. expressionless; blank (variant of 呆 dāi)