to put together people or things that are unsuitable for each other

I always thought Chris and Monique were mismatched, so I wasn't surprised when they got divorced. 我一直认为克里斯和莫妮克不般配，所以他们离婚我并不吃惊。

an occasion when people or things are put together that are not suitable for each other

There is a mismatch between the capacity of the airport and the large number of people wanting to fly from it. 机场的容量与其巨大的客流量很不相称。