English
floodwall
From flood + wall.
Proto-Indo-European *pleh₃(w)- ‘to swim, flow’
Proto-Germanic *flōduz ‘river’
Proto-West Germanic *flōdu ‘river’
Old English flōd ‘flowing of the tide’
Middle English flod ‘a river; a waterbody that moves in one direction’
English flood
Proto-Indo-European *welH- ‘to turn’
Latin vallum ‘wall’
Proto-West Germanic *wall ‘wall’
Old English weall ‘wall’
Middle English wal
English wall
Today it means
noun A man-made vertical barrier designed to temporarily contain the waters of a river or other waterway during a flood
Language periods are conventional ranges, not dates for this word.
Etymograph / floodwall