1 (n. and v.) Procedures or methods used in a program aimed at achieving a particular goal, such as infection control, pest control.
2 (n. and adj.) Person or persons whose characteristics are used for comparison purposes with a person or persons being studied, as in a case control study or a clinical trial
3 (v.) To regulate, adjust. This word is frequently used, sometimes overused, in many aspects of public health and epidemiology. Its meaning is usually clear from the context.