Something inevitable is going to happen and it can't be stopped.
When we talk about something being inevitable, we usually mean that it's pretty much set in stone. It's not like you have a choice or you can do anything to change the course of events. Think about it like a train on tracks - once it starts moving, it's going to keep going until it reaches its destination. When someone says "the rain is inevitable today" they mean that it's definitely going to happen, no matter what. Or if someone says "I'm getting older and retirement is inevitable", they're saying that it's just a part of life and can't be avoided.
Something that is predictable, necessary, or cannot be avoided.
Impossible to avoid or prevent.
Example: We were going so fast that the collision was inevitable.
