致命的

1. Origins, structure, and basic meaning

• Structure: 致命的 is read as ちめいてき and means fatal or critical enough to threaten life, success, or continued viability.
• Basic usage: Use 製品には致命的だ for judging something fatal to a product and 致命的な影響 for a critical or fatal effect.

2. Common pitfalls and similar expressions

• Difference between 致命的 and 重大
  • The former suggests decisive, potentially irreparable damage, whereas the latter says that an issue or effect is very serious or important.