English
lowpass
From low + pass.
Proto-Indo-European *legʰ- ‘to lie’
…
Proto-Germanic *ligjaną ‘to lie’
Proto-Germanic *lēgaz ‘low’
Old Norse lágr
Middle English lāh
English low
Proto-Indo-European *peth₂- ‘to spread, stretch out’
…
Latin passus ‘a step’
Vulgar Latin *passō ‘to step, walk, pass’
Old French passer ‘to step, walk, pass’
Middle English passen ‘to pass’
English pass
Today it means
adj Describing a filter, circuit, or system that rejects or attenuates a frequencies above a specified value while passing those be.
Language periods are conventional ranges, not dates for this word.
Etymograph / lowpass