gastric juice: digestive secretions of the stomach glands consisting chiefly of hydrochloric acid and mucin and the enzymes pepsin and rennin and lipase
abstraction: a general concept formed by extracting common features from specific examples
planck's law: (physics) the basis of quantum theory; the energy of electromagnetic waves is contained in indivisible quanta that have to be radiated or absorbed as a whole; the magnitude is proportional to frequency where the constant of proportionality is given by Planck's constant