Satellite Pass
A satellite pass is one satellite's single overflight of a location: nothing filled in, nothing smoothed over. Where cloud blocked the sensor during that specific overflight, the pass simply has no reading there, usually a few hours old by the time it reaches Chlorofishy.
A pass is the opposite of a composite, which blends multiple sensors to fill gaps a single pass leaves open. Full comparison: raw pass vs. composite SST.