IPA: /ˈniːtli/
KK: /ˈnitli/
In a tidy and organized way, without mess or disorder.
She arranged the books neatly on the shelf.
Neatly → It is formed from "neat" (from Old English *neat*, meaning tidy or clean) and "-ly" (meaning in a manner of). The word "neatly" means in a tidy or clean manner.
Think of being tidy or clean ('neat') and how the '-ly' suffix indicates the manner of doing something. So, when you think of 'neatly', picture doing things in a tidy way.