If you're verbose, you use far more words than you need to. A verbose book report goes on and on and is packed with long, complicated words that aren't at all necessary.
If a friend asks, "Did you have fun at the party?" you can simply answer, "No." Or you can provide a verbose reply that describes just how much you hated the party, who was and wasn't there, the fact that you got lost on the way, the terrible food that was served, and the awful music that was played. Verbose is from Latin verbosus "full of words," from verbum, "word or verb." As you can guess from the spelling, the English verb is closely related.