πύρωσις/purōsis

This word is an idea. It is a noun.

This word can mean a burning.
This word can mean a fiery test or a refining test. This is the act of testing metal or making metal pure by heating it in a fire.
This word can mean something that is like a fiery test in some way.

See: 1 Peter 4:12; Revelation 18:9, 18