ləˈplä]sə̇z-, -pla] noun
Usage: usually capitalized L
Etymology: after Pierre Simon de Laplace died 1827 French astronomer and mathematician
: the equation ∂²u/∂x² + ∂²u/∂y² +∂²u/∂z² = 0 often written ∇ 2 u = 0 in which x,y, and z are the rectangular Cartesian coordinates of a point in space and u is a function of those coordinates