the world > space > extension in space > measurable spatial extent > vertical extent > shallowness > [noun]
scheldhedc1450
shallowness1552
ebbness1637
c1450 Jacob's Well (1900) 168 A skete also sumdel, in þe heuyd, is raysed & reryd on bothe sydes; for ellys it myȝt noȝt receyvin but lytel wose for scheldehed, for to castyn it out.