pepsinogen. a zymogen secreted by the chief cells of the gastric glands and converted into pepsin in the presence of gastric acid or of pepsin itself.plasma pepsinogen. high levels are indicative of extensive mucosal damage in the abomasum, as in ostertagiasis in ruminants. proenzyme formed and secreted by the chief cells of the gastric mucosa; the acidity of the gastric juice and pepsin itself remove 42 amino acid residues from pepsinogen to form active pepsin. Synonym(s): propepsin. [ pepsin + G. -gen, producing].
Princeton's WordNet(5.00 / 1 vote)Rate this definition: 1  reed(noun) tall woody perennial grasses with hollow slender stems especially of the genera Arundo and Phragmites.
The reed is fixed onto the mouthpiece of the clarinet so that only a very narrow opening remains between the tip of the reed and the mouthpiece. When you close your lips around the mouthpiece and the reed and blow, a tone is created.