瞬時

1. Origins, structure, and basic meaning

• Structure: 瞬時 is read as しゅんじ and is a noun for an extremely short time in which an action or change occurs without perceptible delay.
• Basic usage: It commonly functions adverbially with に, as in 瞬時に姿を隠す and 瞬時に記録する.

2. Common pitfalls and similar expressions

• Difference from 瞬間
  • 瞬間 broadly names a particular moment; 瞬時 often emphasizes how immediately an action is completed.
• Tone versus 刹那
  • Both are very brief, but 瞬時 neutrally suits rapid actions and devices, while 刹那 is more literary or dramatic.