[packjaddison]

In my head, after 'thumb-under', I think of 'skips' and 'leaps' depending on distance for whole-hand repositioning, which is descriptively accurate for fingering on the piano, guitar, and violin (etc.). Though, for the novice I could see how conceptualizing a movement this way could interfere with legato technique, as it encourages more discrete chunking than does the 'unbroken' thumb-under during a run. Does that nomenclature match your conceptualization at all?