a. (People or writing) 说话,言语絮絮叨叨，繁冗拖沓；
c. (Things)琐碎;麻烦的 (when you need to go through very complicated processes to get things done)
啰嗦 simply means someone is doing things or saying (expressing or explaining) things in an unnecessarily complicated way.
Keep in mind that 啰嗦 is used to show disapprove, it is also a subjective term, which means this phrase is used when you are annoyed with the way someone is doing things or the way things are done.
If your mom told you not forget to take the umbrella just in case, you would kiss your mom and say thanks; but if your mom said that ten times during your breakfast, you would feel annoyed and say "妈妈，别啰嗦了，您都说十遍了，我知道了"
But if your husband or your boyfriend says "I love you" to you, I believe you will be very happy to hear that; you wouldn't feel annoyed or use "你也太啰嗦了' even he said that one hundred times in a day.