1 [I] clash (with sb) (over sth) to fight or disagree seriously about sth 角斗；激辩；冲突: A group of demonstrators clashed with police outside the Town Hall. 市政厅门外一群示威者跟警方发生冲突。

2 [I] clash (with sth) (used about two events) to happen at the same time （指两件事）（日程、时间等）撞期，有冲突: It's a pity the two concerts clash. I wanted to go to both of them. 真可惜，两场音乐会时间撞期，我原来想两场都去呢。

3 [I] clash (with sth) (used about colours, etc) to not match or look nice together （指颜色等）不调和: I don't think you should wear that tie -- it clashes with your shirt. 别结这条领带，它跟你的衬衫色彩不协调。

4 [I,T] (used about two metal objects) to hit together with a loud noise; to cause two metal objects to do this （指两件金属物体）（使）砰然相撞: Their swords clashed. 他们的剑斗得铿锵作响。