[robocat]

xrun definition: https://unix.stackexchange.com/questions/199498/what-are-xru...

(I didn't know the term, trying to be helpful if others don't)

[tinix]

just a buffer under/overrun

[snvzz]

it's cross-run aka xrun because these buffers are circular.

Depending on implementation, it will either pause or play the old sample where the new one isn't yet but should be.