ex·pound 
/ɪkˈspaʊnd/ verb
ex·pounds; ex·pound·ed; ex·pound·ing /ɪkˈspaʊnd/ verb formal : to explain or state (something) : to give details about (something) [+ obj] ▪ The article expounds the virtues of a healthy diet. [no obj] ▪ When asked to expound, he had no comment. — often + on ▪ The article expounds on the virtues of a healthy diet.
