(of one out of a group of related or otherwise associated people) of the greatest age; oldest 年龄最大的;最老的 Swift left the company to his eldest son, Charles. 斯威夫特把公司留给了大儿子,查尔斯。 he was the eldest of the three. 他在三人中年龄最大。
语源
Old English ieldest, eldest, of Germanic origin; related to German ältest, also to eld and old