How to turn off getter/setter only for one instance non-final field? [Project Lombok]

You can use @Getter(AccessLevel.NONE) @Setter(AccessLevel.NONE) on the field as described on the website.

Disclosure: I am a Lombok developer.

In order to avoid generating Getter/Setter for a specific field, you can use AccessLevel.NONE, as described in webpage for Getter/Setter

@Data
public class Person {
    private String name;
    private int age;
    @Getter(AccessLevel.NONE) @Setter(AccessLevel.NONE)
    private Map<String, String> dialog;
}

EDIT: This answer originally proposed to use AccessLevel.PRIVATE. The correct approach is to use AccessLevel.NONE as @Roel_Spilker mentioned in the other answer. But this answer was accepted by the questioner. In order to avoid future confusion, I edited this to use correct approach.