Code freeze
Also called: release freeze, change freeze, freeze window
A code freeze is a period in which changes to production, or to a release branch, are restricted in order to reduce risk.
Teams freeze before a major release or over a holiday period, when fewer people are available to respond if something goes wrong. A freeze trades delivery speed for stability during a window where recovery would be slow.
The debate between freezing and continuous delivery is usually framed as a matter of courage. The practical question is what kind of change is being deployed and who could fix it. A copy change and a payment refactor should not face the same bar in mid-December.
A freeze also stores up work. I ask for the deferred items to be listed with owners before the freeze starts, so that the first release afterwards is planned and not a surprise.