English
protocyanide
From proto- + cyanide.
Proto-Indo-European *pér ‘through’
Proto-Indo-European *pró ‘forwards, before’
Proto-Hellenic *pró
Ancient Greek πρό ‘before’
Ancient Greek πρῶτος ‘first’
English proto-
Today it means
noun Any of a series of cyanides of a particular metal that has the fewest cyanide groups per molecule
Language periods are conventional ranges, not dates for this word.
Etymograph / protocyanide