to play dumb; to feign ignorance; to act innocent or blank to avoid answering or admit something.
彼は私の問いにとぼけて「知らないよ」と言った。
He played dumb at my question and said, 'I don't know.'
子どもが悪さをして、とぼけた顔でごまかそうとした。
The child tried to cover it up with a blank, innocent look after misbehaving.
彼は証拠を突きつけられてもとぼけ続けた。
Even when confronted with evidence, he kept pretending not to know.
to play the fool; to act silly or clownish (often to lighten the mood or amuse others).
彼は場を盛り上げようととぼけてみせた。
He acted the fool to liven things up.
コメディアンが舞台でとぼけて観客を笑わせた。
The comedian played the fool on stage and made the audience laugh.
(archaic/dated) to be in one's dotage; to become senile or forgetful with age (rare/old-fashioned usage).
古い日記には『近ごろ惚けて物忘れが多し』と書かれている（古い用法）。
An old diary reads, 'Lately I'm growing forgetful,' (an old-fashioned usage).