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