From WordNet (r) 3.0 (2006) :
reboot
v 1: cause to load (an operating system) and start the initial
processes; "boot your computer" [syn: boot, reboot,
bring up]
From The Free On-line Dictionary of Computing (30 December 2018) :
reboot
(From boot) A boot with the implication
that the computer has not been down for long, or that the
boot is a bounce intended to clear some state of
wedgitude.
See warm boot.
(1995-11-27)