exponent

Universal Words noun 1 a person who supports an idea, theory, etc. and persuades others that it is good: She was a leading exponent of free trade during her political career * Huxley was an exponent of Darwin's theory of evolution. 2 a person who is able to perform a particular activity with skill: the most famous exponent of the art of mime 3 (mathematics) a raised figure or symbol that shows how many times a quantity must be multiplied by itself, for example the figure 4 in a4 \