/ ɪkˈspəʊnənt; NAmE -ˈspoʊ-/ noun
a person who supports an idea, theory, etc. and persuades others that it is good
SYN proponent :
She was a leading exponent of free trade during her political career
a person who is able to perform a particular activity with skill :
the most famous exponent of the art of mime
( mathematics ) a raised figure or symbol that shows how many times a quantity must be multiplied by itself, for example the figure 4 in a 4
late 16th cent. (as an adjective in the sense expounding ): from Latin exponent- putting out, from the verb exponere expose, publish, explain, from ex- out + ponere put.