na-adjective, noun which may take the genitive case particle 'no', noun
Describes a person or action lacking emotion, empathy, or warmth; often used in literary or dramatic contexts.
He is said to be a cold-blooded person.
The cold-blooded murderer was finally arrested.
冷血 describes a cold, unfeeling temperament, the direct opposite of the fiery passion implied by 熱血.
From 冷 (cold) + 血 (blood), literally 'cold blood'. The figurative meaning of lacking emotion is shared with English 'cold-blooded'.