| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
control con·trol (kən-trōl')
v. con·trolled, con·trol·ling, con·trols
To verify or regulate a scientific experiment by conducting a parallel experiment or by comparing with another standard.
To hold in restraint; check.
A standard of comparison for checking or verifying the results of an experiment.
An individual or group used as a standard of comparison in a control experiment.
| control (kən-trōl') Pronunciation Key
A standard of comparison for checking or verifying the results of an experiment. In an experiment to test the effectiveness of a new drug, for example, one group of subjects (the control group) receives an inactive substance or placebo , while a comparison group receives the drug being tested. |