Urticariaâthe scientific name for hivesâis an outbreak of red, swollen, and itchy welts that form on the skin. Hives appear suddenly and can appear anywhere on the body, including the face, lips and throat. They typically vary in size, and may join together to form larger welts.
Define effectivity. effectivity synonyms, effectivity pronunciation, effectivity translation, English dictionary definition of effectivity. adj. 1. a. Having an intended or expected effect. b. Producing a strong impression or response; striking: gave an effective performance as Othello.
EFFECT. 1  Something brought about by a cause or agent; a result. 2  The power to produce an outcome or achieve a result; influence: The drug had an immediate effect on the pain. The government's action had no effect on the trade imbalance. 3  A scientific law, hypothesis, or phenomenon: the photovoltaic effect.