substance
n
1 the tangible matter of which a thing consists
2 a specific type of matter, esp. a homogeneous material with a definite composition
3 the essence, meaning, etc., of a written or spoken thought
4 solid or meaningful quality
5 material density
a vacuum has no substance
6 material possessions or wealth
a man of substance
a the supposed immaterial substratum that can receive modifications and in which attributes and accidents inhere
b a thing considered as a continuing whole that survives the changeability of its properties
8 (Christian Science) that which is eternal
9 ♦
in substance with regard to the salient points (C13: via Old French from Latin substantia, from substare, from sub- + stare to stand) ♦
substanceless adj
amount of substance
n a measure of the number of entities (atoms, molecules, ions, electrons, etc.) present in a substance, expressed in moles
growth substance
n (Botany) any substance, produced naturally by a plant or manufactured commercially, that, in very low concentrations, affects plant growth; a plant hormone
queen substance
n a pheromone secreted by queen honeybees and consumed by the workers, in whom it causes suppression of egg-laying
working substance , fluid
n the fluid, esp. water, steam, or compressed air, that operates an engine, etc.