n (1)跨距 (径) (bridge's or arch's length between its supports)[C]：the second～of the bridge 桥的第二孔;a bridge of four～s 四孔桥;The middle～of the bridge is one hundred feet long. 这座桥的中间一孔跨距为100英尺。The arch has a～of 40 metres. 这道拱门的跨距为40米。The bridge crossed the river is a single～. 河上那座桥是单孔桥。〖同〗arch，archway，wing，extension;

(2)(一段持续的)时间(period or length of time over which sth continues or lasts)[C]：over a～of eight years八年期间;a short～of time 一段短时间;His～of life is over. 他的一生结束了。a concentration/attention/interest/memory～集中注意力/注意/兴趣/记忆持续的时间;

(3)指距，一拃宽(distance between the tip of the thumb and the tip of the little finger when the hand is fully extended)[C](旧用法)：measure by～s 用拃量;

vt(1)横跨，跨越(provide with sth that extends over)[T+n]：～a river with a bridge 在河上架桥;A bridge～ned the river/the railroad/the bay. 一座桥跨越在河/铁路/海湾上。An overpass～ned the centre of the town. 一座立交桥跨越镇中心。The river is～ned by many bridges. 这条河上架有许多桥梁。〖同〗bridge，cross;

(2)贯穿，持续(extend，reach or pass over(space or time))[T+n](fml)：Her knowledge/interests～ned many areas (subjects). 她的知识/兴趣涉及许多领域(学科)。His life～ned the whole of the 18th century. 他的一生跨过了整个18世纪。His career～ned three decades. 他的事业持续了30年。Their friendship～ned a lifetime. 他们的友谊保持了一生。～all professions 包括各行各业;〖同〗cover，last，endure，survive;

(3)以指量距(测量)(stretch one's extended hand over or across in one span)[T+n]：～the intervening space 测量间隔的距离;～an octave on the piano 一拃按钢琴的八个键;

【注意】此字和 spin 的过去式 span 读音、拼写相同。