I am doing some research on virtualization and came across two separate accounts of people claiming to have coined the term "hypervisor." The first was ex-IBMer Don Skiba circa 1966 via this ZDNet blog:

"We tossed around a lot of names for code at the time.  I suggested that
"hypervisor" might be appropriate, because, prior to the 360, there
were no "operating systems" and the prior systems all had
"supervisors".  So, "hypervisor" seemed appropriate and the name stuck.
It was a very successful program. "

The second was Dave Tuttle in Wikipedia’s discussion section on the word Hypervisor:

"BTW, the term "hypervisor" was most likely coined by me in late 1971,
during CP development for VM/370. We had to pick new source filenames
and external symbol names for all of the CP functions, to conform to
IBM SCP nomenclature. One of the modules I wrote was the handler for
the Diagnose instruction, and I called it DMKHVC, for Hypervisor Call."

Just thought it was interesting.