bull’s-eye有这几个意思：1.最常见的意思是指 the small central circle on a target；a shot that hits this circle.靶心;打中靶心的一击;直接命中如：The archer’s shot was a perfect bull’s-eye.射手的那一箭正中靶心。引申的意思有：2. 事物的关键,中心要点3. 击中要害的话(或行动)
固定表达
hit a bull’s eye:命中靶心，达到预定目标，取得成功.
In target shooting: a score made by hitting the center of the target
He hit a bull’s eye in their argument with that witty retort.
他以机智的反驳赢得了辩论胜利。