a synthetic, amphetamine-like, crystalline drug, CHNO·HCl, that constricts the blood vessels, used in nasal decongestants, diet pills, cough medicines, etc.
See phenylpropanolamine in American Heritage Dictionary 4
noun Abbr. PPA
An adrenergic drug, C9H13NO, that acts as a vasoconstrictor and is used as a nasal decongestant, bronchodilator, appetite suppressant, and mild stimulant.