co ‧ balt /ˈkəʊbɔːlt $ ˈkoʊbɒːlt/ BrE AmE noun [uncountable]
[ Date: 1600-1700 ; Language: German ; Origin: kobalt , from kobold 'goblin' ; because goblins were thought to mix it in with silver found in the ground ]
1 . a shiny silver-white metal that is often combined with other metals or used to give a blue colour to substances such as glass. It is a chemical ↑ element : symbol Co
2 . ( also cobalt blue ) a bright blue-green colour
—cobalt adjective