IPA: /pərˈfɔːrs/
KK: /pɚˈfɔrs/
By necessity or because of the situation; it indicates that something must happen due to circumstances beyond control.
The project was delayed, and perforce, we had to extend the deadline.
Perforce → It is formed from "per" (meaning through) and "fortis" (meaning strong or force). The word "perforce" means by force or necessity, implying that something is done through strong compulsion or necessity.
Think of doing something 'through' ('per') strong 'force' ('fortis') — that's why perforce means by necessity or force.