Neapolitan has a variety of terms of endearments, many of which have rather vulgar roots, though there are several that simply are used in an endearing way.

Linella - literally means little girl

Com' bell[e] sta linella - literally means "the little girl is so beautiful", this is the kind of saying you would say when seeing your friends new baby or a young child that you know.

Un piezz' d' cuore - literally means a piece of heart, but its use to mean you are a piece of my heart

Chiacchiaróne - big talker, chatterbox, one whose hard to believe

The giving of nicknames is another type of typical Neapolitan way of showing endearment. Typically these names are given to a particularly unique physical characteristic, which may not always be positive, but the naming still takes on a kind element. Often a person's facial features might be compared to a typical kind of produce or food in Naples. Sometimes their personality or habits could be related to a type of food, for example "capocitrulo (cucumber-head)" shows a simplemindedness. Writer, Alfonso Guerriero explains, "additional monikers in the vegetable category used as nicknames by Neapolitans are: cucuzziello =zucchini, puparulo =peppers, pumbarlo =tomatoes, fusulo =beans, scarola =escarole, patanaro =potato. I recall one family was given the nickname famiglia patanaro because they would eat potatoes every day." (https://italoamericano.org/story/2013-8-29/Neapolitan-Nickname)