To grow senile or to experience cognitive decline with age; a colloquial term for becoming forgetful or losing sharpness.
祖父は最近少しボケてきたようだ。
My grandfather seems to be getting a bit senile lately.
年を取ると記憶が薄れてボケることがある。
As people age, memories fade and they can become senile.
彼は呆けて窓の外を見ている。
He is zoned out, staring out the window.
To be mentally slow or befuddled — to be absent-minded or slow to respond; can be temporary due to tiredness or sleepiness.
今日は頭がボケていて計算ができない。
My mind is foggy today and I can't do calculations.
眠くてボケているからミスが多い。
I'm sleepy and out of it, so I make a lot of mistakes.
彼女は一瞬ボケて答えられなかった。
She blanked for a moment and couldn't answer.
To play the fool or act stupid deliberately as part of comedy (the boke role in manzai), or to say something silly on purpose to get laughs.
あの芸人はいつも舞台でボケて笑いを取る。
That comedian always plays the fool on stage to get laughs.
彼はわざとボケて会話を面白くした。
He intentionally acted silly to make the conversation funnier.
コンビのボケとツッコミのバランスが大事だ。
The balance between the boke and tsukkomi in a comedy duo is important.