Definition of control-alt-delete in US English:

control-alt-delete

(also ctrl-alt-delete, ctrl-alt-del)

noun

Computing
  • A combination of three simultaneous keystrokes which causes an IBM-compatible PC to restart or (in later systems) allows the user to select from a menu of system tasks, such as logging out, restarting the computer, or closing a program; also in figurative contexts.

Origin

1980s; earliest use found in PC Magazine.