principle

(prin'sl-pl) [L. principium; princeps, chief.] I. A continuously acting power or force. 2. The e ential ingredient in a drug or chemical compound, active p., a constituent of a drug, usually an alkaloid or glucoside, upon the presence of which the characteristic therapeutic action of the substance largely depends, organ'- ic p., proximate p. proz'imate p., in chemistry an organic compound which may exist already formed as a part of some other more complex substance various sugars, starches, and albumins belong to this cla of substances, ul'timate p., one of the chemical elements.