The word "proc" is used to describe an event that occurs at various intervals and seems to be a term unique to programming and gaming:
When does that event proc?
If that trigger procs it will cause [...]
This card has an ability that procs when you play [...]
When the card proc'ed/procced, it killed off all opposing creatures and won me the game.
The word does not appear in the dictionaries I checked. "Proc" is listed as an abbreviation for words like "proceeding":
But these seem completely unrelated to the usage I've noted above. So where did this term originate?