Adding information that supports what’s already been said…
Use the adverb moreover to add information that supports what’s already been said. You have to go shopping on Saturday to buy new tube socks, and moreover, you need to get a birthday present for your mom.
Breaking moreover into more and over helps you remember what it means: more information over what has already been said. When you hear someone use moreover that tips you off that whatever follows is going to relate to what came before. You can think of moreover as a formal way of saying besides. You may be sick of your brother always getting out of doing the chores, and, moreover, the guy has a really bad attitude about taking on responsibility.
Thanks to Vocabulary.com