What is an ace in childhood trauma?

Excuse me, could you please elaborate on the term "ace in childhood trauma"? I'm not entirely familiar with this specific phrase, and I'm curious about its meaning in the context of childhood experiences that may cause emotional distress. Is it a reference to a particular type of trauma, or is it a colloquial way of describing someone who has experienced significant adversity during their childhood? Additionally, I'm wondering if there are any recognized psychological frameworks or theories that this term relates to, and how it might be used in discussions about childhood trauma and its long-term impacts.