English
foreperiod
From fore- + period.
Proto-Indo-European *per- ‘before, formerly’
Proto-Germanic *fura- ‘before, in front of, for’
Proto-West Germanic *forē- ‘before, in front of, fore-, pre-’
English fore-
Ancient Greek περῐ́οδος ‘circuit, orbit, recurring interval of time’
Medieval Latin periodus
Middle French periode
Middle English periode
English period
Today it means
noun A time interval, in reaction time experiments, between the ready signal and the stimulus
Language periods are conventional ranges, not dates for this word.
Etymograph / foreperiod