A very massive
blackhole. A supermassive blackhole is larger than a
mega-blackhole, but smaller than a
hyper-supermassive, (ie. hypermassive) blackhole.
'Two mega-blackholes merged to form one so massive that it became a supermassive blackhole, but even that's
nothing compared to the size of a hypermassive blackhole.'
(
Please read my
definition of a mega & hypermassive blackhole for more information).