What it is
Labeling is one of the ten cognitive distortions David Burns listed in Feeling Good (1980). It’s an extreme kind of overgeneralizing: instead of describing what happened, you stick a global label on yourself or someone else. “I made a mistake” becomes “I’m a loser.” “He was late” becomes “he’s useless.”
Mislabeling is the cousin: describing an event in loaded words that carry the verdict inside them.
How it shows up for me
I catch myself doing it to people faster than to myself, and to myself more cruelly. The fix is boring and it works: say what was done, and stop there.