Meaning of EFFECTIVE in English

I. adjective Date: 14th century 1. producing a decided, decisive, or desired effect , impressive , striking , ready for service or action , actual , being in effect ; operative , equal to the rate of simple interest that yields the same amount when the interest is paid once at the end of the interest period as a quoted rate of interest does when calculated at compound interest over the same period, ~ness noun effectivity noun Synonyms: see: ~ II. noun Date: 1722 one that is ~

Merriam Webster. Explanatory English dictionary Merriam Webster.      Толковый словарь английского языка Мерриам-Уэбстер.