From The Free On-line Dictionary of Computing (19 January 2023):
dump
<operating system> 1. An undigested and voluminous mass of
information about a problem or the state of a system,
especially one routed to the slowest available output device
(compare core dump), and most especially one consisting of
hexadecimal or octal runes describing the byte-by-byte
state of memory, mass storage, or some file. In elder days,
debugging was generally done by "groveling over" a dump (see
grovel); increasing use of high-level languages and
interactive debuggers has made such tedium uncommon, and the
term "dump" now has a faintly archaic flavour.
2. A backup. This usage is typical only at large
time-sharing installations.
Unix manual page: dump(1).
(1994-12-01)