せずに

adverb

without doing; instead of doing

Negative adverbial form related to する: used after verbal nouns as ～せずに, as in 確認せずに, or by itself to mean 'without doing so.' It is a little more formal or written-sounding than しないで.

• メールを確かく認にんせずに送おくってしまった。

  I sent the email without checking it.

• 彼かれは返へん事じをせずに部屋へやを出でた。

  He left the room without replying.