cold-blooded vs inhuman

cold-blooded and inhuman both are adjectives.

Word	Noun	Adjective	Verb	Adverb
cold-blooded	No	Yes	No	No
inhuman	No	Yes	No	No

As adjectives, cold-blooded and inhuman are synonyms defined as:

Other synonyms of cold-blooded include cold, insensate.

cold-blooded (adjective)	inhuman (adjective)
having cold blood (in animals whose body temperature is not internally regulated)	without compunction or human feeling
without compunction or human feeling	belonging to or resembling something nonhuman