The word "moreover" is a transition word that is used to add information in a way that emphasizes an additional point. It introduces a statement that reinforces or expands on what has been previously said, effectively meaning "in addition to" or "furthermore."
The word "moreover" comes from the Middle English "more over," which means "in addition to" or "further." It combines "more," from Old English “māra,” meaning "greater" or "additional," and "over," from Old English "ūfer," used here to indicate something adding or supplementing.