Perforce is an adverb that is used to express necessity.

Our word of the day comes directly from Middle English, meaning ‘by force.’ When we do something perforce, we do it because we’re forced to do so out of social or practical necessity. For example: When I asked Eric how things were going, I was doing so perforce, not because I wanted an answer. But Eric gave me a forty-five minute update on exactly how things were going.