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)
en-GB/ˈfɪzɪkl ˈsʌbstəns/
en-US/ˈfɪzɪkəl ˈsʌbstəns/