physical substance
substance composed of quantum particle(s)/field(s), such as matter and/or radiation; that of which objects/systems are composed; physical stuff that can be considered concrete (not strictly abstract)
matter
substance that has rest mass and volume
continuum
material modelled as a continuous medium rather than as discrete particles
dark matter
mysterious non-luminous matter (and/or radiation) comprising most of the matter in our observable universe
field
physical quantity, represented by a number or tensor, that has a value for each point in space-time
pollutant
substance or energy source damaging to the environment
groundmass
groundmass in igneous and metamorphic rocks is comparable to the matrix in sedimentary rocks; fine-crystalline mass in which the coarser crystals "float"