autodegradar

To degrade oneself, especially verbally — putting oneself down, often in self-deprecating speech that goes beyond healthy humility: no dejes que se autodegrade delante de todos. Less common than related self- verbs, mostly seen in psychology and self-help writing.

• No dejes que se autodegrade delante de todos con esos comentarios. — Don't let him degrade himself in front of everyone with those comments.
• El humor autodegradante puede esconder una autoestima muy baja. — Self-deprecating humor can mask very low self-esteem.
• Se autodegradó tanto en la entrevista que el jefe empezó a dudar de él. — He put himself down so much in the interview that the boss started to doubt him.

Confusing autodegradar with the environmental sense of degradar (a material breaking down) — with the auto- prefix and a person as subject, it's specifically about self-deprecating speech or behavior, not physical decomposition.

Often confused with degradar.