Remember, expound means to explain something in detail, expand means to add detail to an explanation that has already been given. Expand is a verb that is derived from the Latin word expandere which means to unfold, to spread out. Related words are expands, expanded, expanding, expander.

Expound means to explain something in detail, to set forth an argument. Expound is a transitive verb, which is a verb that takes an object. Related words are expounds, expounded, expounding, expounder. The word expound is derived from the Latin exponere, which means to expose, to put forth, to offer,...

‘Expound this matter more fully to me.’; To rewrite (an expression) as a longer, yet equivalent sum of terms. ‘Use the binomial theorem to expand’; ‘x 4 + 4x 3 + 6x 2 + 4x + 1.’; add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing;

is that expound is to lay open; to expose to view; to examine or exposit while elaborate is (used with” on ”when used with an object ) to give further detail or explanation (about). What does Exposit mean? (ɪksˈpɒzɪt ) verb (transitive) to expound; to demonstrate clearly.