English
floatstone
From float + stone.
Proto-Indo-European *plewd- ‘to float, swim, fly’
Proto-Germanic *flutōną ‘to float’
Proto-West Germanic *flotōn ‘to float’
Old English flotian ‘to float’
Middle English floten ‘to float’
English float
Proto-Indo-European *steyh₂- ‘to stiffen’
…
Proto-Germanic *stainaz
Proto-West Germanic *stain
Old English stān
Middle English ston ‘a stone’
English stone
Today it means
noun A kind of calcareous rock, more than 10% of which is made up of grains larger than two millimetres, and which is matrix-supported.
Language periods are conventional ranges, not dates for this word.
Etymograph / floatstone