To press someone with repeated or forceful questioning in order to extract the truth or an answer; to cross-examine or confront persistently.
上司はミスの責任を彼に問い詰めた。
The boss pressed him about responsibility for the mistake.
子どもが帰りが遅い理由を母親に問い詰められて、困っていた。
The child was troubled because his mother kept pressing him about why he came home late.
検事は証人を厳しく問い詰めた。
The prosecutor cross‑examined the witness harshly.