D defs.my
Entry 1 sense Webster, 1913

Protometals

· Pro·to·met·als · IPA
01 n. pl. A finer form of metals, indicated by enhanced lines in their spark spectra (which are also observed in the spectra of some stars), obtained…
  1. 1.
    A finer form of metals, indicated by enhanced lines in their spark spectra (which are also observed in the spectra of some stars), obtained at the highest available laboratory temperatures (Lockyer); as protocalcium, protochromium, protocopper, protonickel, protosilicon, protostrontium, prototitanium, protovanadium.