Outlier video
Also called outlier · breakout video
A video that performed far above the normal range for its channel, usually expressed as a multiple of that channel's recent median views.
In more detail
Outlier is a relative measure, not an absolute one. A video with 40,000 views on a channel that normally gets 4,000 is a stronger outlier than a million-view video on a channel that always gets a million. Research tools compute the multiple against a channel's own recent uploads, which is what makes small channels' breakouts visible at all.
Example
Scanning a niche for videos at several times their channel's median surfaces topics and angles that beat expectations rather than videos that are merely popular. The second list is mostly large channels; the first is where a pattern worth copying tends to hide.
Why it matters
Outliers are the most useful research signal available and the easiest to over-read. One video at five times median is noise as often as it is a finding, and the same topic on a channel with a different audience may do nothing. The defensible use is to look for a pattern repeated across several unrelated channels, then treat it as a hypothesis rather than a formula.