to set forth or state in detail: to expound theories.
2.
to explain; interpret.
verb (used without object)
3.
to make a detailed statement (often followed by on ).
Origin: 1250–1300;Middle Englishexpounen,expounden < Old Frenchespondre < Latinexpōnere to put out, set forth, explain, equivalent to ex-ex-1 + pōnere to put
c.1300, from O.Fr. expondre, from L. exponere "put forth, explain," from ex- "forth" + ponere "to put, place" (see position); with intrusive -d. Related: Expounded; expounding.