a small opening that allows air, smoke, or gas to enter or leave a closed space

If you have a gas fire in a room, you should have some kind of outside vent. 如果你的屋里有煤气炉，那你就应该有个通向外面的排气口。

a cut in the bottom of a piece of clothing to allow the person wearing it to move more easily

The skirt is long and straight with two side vents. 这条裙子是很长的直筒裙，两侧开衩。

to express a negative emotion in a forceful and often unfair way

The meeting will be an opportunity for everyone to give vent to their feelings. 这次会议将给每个人一吐为快的机会。

to express a negative emotion in a forceful and often unfair way

Please don't shout - there's no need to vent your frustration/anger/rage/spleen on me. 请不要大吵大闹——没有必要把气撒在我身上。

I didn't mean to upset anyone, I just needed to vent. 我没想要针对任何人，我只是想发泄一下。