ancestor
/ˈænsestə(r); `ænsɛstɚ/ n
1 (fem 阴性作 ancestress / -trɪs; -trɪs/) any of the people from whom sb is descended, esp those more remote than his grandparents; forefather 祖先; 祖宗
His ancestors had come to England as refugees. 他的祖先来到英国的时候是难民. Cf 参看 descendant (descend).
2 (fig 比喻) early form of a machine or structure which later became more developed; forerunner 原型（某机器或结构的早期形式）; 先驱
The ancestor of the modern bicycle was called a penny farthing. 现代自行车的原型叫做‘前轮大後轮小的自行车’.