systemctl mask

Make a unit impossible to start

high risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
Safer / dry-run alternatives
systemctl unmask <unit>Undo
systemctl disable --now <unit>Less drastic
What it does

Links the unit to /dev/null. See the flags and examples below, and run `man systemctl` for the full reference.

Examples
systemctl mask sleep.targetMask · explain & risk-check →
systemctl unmask sleep.targetUndo · explain & risk-check →
Related
systemctl disable
Open the full explainer →More in System & Processes

Reference text is hand-written and may be incomplete — check man systemctl for your version. Test destructive commands on a non-production system first.