perforce
adverb /pəˈfɔːs/
/pərˈfɔːrs/
(old use or formal)- because it is necessary or cannot be avoided
必须；必定；势必 - They had perforce to abandon the attempt on the summit.
他们不得不放弃登顶的尝试。
词源Middle English: from Old French par force ‘by force’. - They had perforce to abandon the attempt on the summit.