一等奖的英文是 "first prize"。
来源：这个词是在表示比赛或竞赛的奖项中使用的，表示获胜者或最高奖项。
例句：
She won the first prize in the national science competition.
她在全国科学竞赛中获得了一等奖。
He was awarded the first prize for his outstanding performance.
他因出色的表现获得了一等奖。
The first prize was a trip to Paris.
一等奖是去巴黎的旅行。