metal vs metal-looking

metal is a noun but metal-looking is not a noun.

Word	Noun	Adjective	Verb	Adverb
metal	Yes	Yes	Yes	No
metal-looking	No	Yes	No	No

metal (noun)	metal-looking (noun)
any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
a mixture containing two or more metallic elements or metallic and nonmetallic elements usually fused together or dissolving into each other when molten

metal (adjective)	metal-looking (adjective)
containing or made of or resembling or characteristic of a metal	resembling metal

metal (verb)	metal-looking (verb)
cover with metal