"Ding-a-ling" is a playful and somewhat derogatory term typically used to describe someone who is absent-minded or eccentric. While it may be a fun term to use in jest, it's important to be respectful of others and avoid using derogatory language that contributes to negative stereotypes.
If you're looking for synonyms for "ding-a-ling", there are plenty of options to choose from. Some possible alternatives include "scatterbrain", "space cadet", "airhead", "wonky", "quirky", "oddball", "eccentric", and "kooky". While these terms can be used to describe someone who is absent-minded or quirky, it's important to use them with a sense of mindfulness and sensitivity towards others.