1. (noun) an odorless very poisonous gas that is a product of incomplete combustion of carbon

• carbon monoxide
• carbon monoxide gas

2. (noun) a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition

• atomic number 27
• cobalt

3. (noun) one who refuses to serve in the armed forces on grounds of conscience

• conscientious objector

4. (noun) a state in west central United States in the Rocky Mountains

• centennial state
• colorado

1. (noun) a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition

• cobalt 60

1. (noun) an odorless very poisonous gas that is a product of incomplete combustion of carbon

• monoxide

2. (noun) a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition

• metal
• metallic element

3. (noun) one who refuses to serve in the armed forces on grounds of conscience

• contestant
• dissenter
• dissident
• objector
• protester