noun which may take the genitive case particle 'no', noun
Describes something that can cause death, often used in medical, toxicological, or safety contexts.
この毒は致死性が高い。
This poison is highly lethal.
致死性の病気が流行している。
A fatal disease is spreading.
Compound of 致死 (ちし, 'causing death') and 性 (せい, 'nature, property').