呆ける

to grow senile; to be childish with age; to be mentally slow; to be befuddled

Meaning

  1. v1vi
    to grow senile; to be childish with age
  2. v1vi
    to be mentally slow; to be befuddled
  3. v1vi
    to play stupid; to say something stupid (oft. on purpose; esp. as part of a comedic routine)