The phrase "hole collisions" refers to situations where multiple holes or openings come together, causing them to bump into each other or potentially block each other's path. Full definition
At the same time, the researchers are upgrading the detectors so that they can spot neutron star and black hole collisions even farther away. (sciencenews.org)
Black hole collisions generally are not expected to result in electromagnetic emissions and none were detected. (sciencedaily.com)
Since that first detection, scientists have observed three more black hole collisions. (sciencenews.org)