Culture Fit
How well a candidate matches the org's vibe. Legitimate at its best; at its worst, a fog machine for 'reminds me of me.' Modern HR prefers 'culture add' for exactly that reason.
Heard in the wild
“Skills were there, but the panel flagged culture fit.”
Tone check: Euphemism
Unexaminable rejections hide in this phrase. Good interviewers can name the specific behavior; ask them to.