It does not exist in Canon Law.
The term was used in the Catholic Church centuries ago. In more recent times it has been exclusively a Protestant term.
Lots of Catholics misuse Catholic terminology.
It appears that defrocking was used before the Vatican II era but it wasn’t equivalent with removing a cleric of all his duties, etc. In the pre-Vatican II era full dismissal was called “degradation”. Laicization appears to be a post Vatican II term and will not be found in the 1917 Code of Canon Law.