noun
or zaf·fre ˈzafə(r) ; also zaf·free -frē ; or zaf·far or zaf·fir -fə(r)
( -s )
Etymology: Italian zaffera, probably from Latin sapphirus sapphire — more at sapphire
1.
a. : an impure cobalt oxide obtained as a dark earthy powder usually by roasting cobaltite or smaltite and used in the manufacture of smalt and as a blue ceramic color
b. : smalt
2. : any of various mixtures of zaffer (as with silica or iron oxide)