phase iv clinical trial: sometimes the FDA approves a drug for general use but requires the manufacturer to continue to monitor its effects; during this phase the drug may be tried on slightly different patient populations than those studied in earlier trials
clinical trial: a rigorously controlled test of a new drug or a new invasive medical device on human subjects; in the United States it is conducted under the direction of the FDA before being made available for general clinical use
queen bee: fertile egg-laying female bee