反义词是formerly，例如：
1、I learnt that the house had formerly been an inn.我得知这座房子以前是家客栈。
2、This fact has led naturalists to believe that the Isthmus was formerly open.使许多自然学者相信这个地蛱在以前原是开通的
3、Many products formerly made of metal now are made of plastic.以前用金属制造的许多产品现在都用所料制造了。
ago，beforetime，formerly，previouslybefore 英[bɪˈfɔ:(r)] 美[bɪˈfɔr，-ˈfor] prep. 在…之前 先于，优于 当着…的面 与其… conj. 在…之前 在…以前 比…早些 与其… adv. 先前，从前 在前，在前方 [例句]Annie was born a few weeks before Christmas安妮出生在圣诞节前几周。
