noun-modifying (irregular)
heavy (in oil, chemistry, etc.)
Technical prenominal adjective used mainly in industrial and chemical contexts, such as describing heavy crude oil or heavy fractions. Not used for general physical heaviness.
See also: 重質油 (じゅうしつゆ)
重質油は精製が難しい。
Heavy oil is difficult to refine.
この装置は重質成分を分離する。
This equipment separates heavy components.