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.
1. efficacy-capacity or power to produce a desired effect; concern about the safety and efficacy of the vaccine. efficaciousness. effectiveness, effectivity, effectuality, effectualness-power to be effective; the quality of being able to bring about an effect. inefficaciousness, inefficacy-a lack of efficacy.