each
When two things are next to each other, like two people who hate each other but still have to be next to each other. That’s called 'each' and it’s the worst kind of torture.
My brother and I are 'each' because we’re stuck next to each other in class.
My boss and I are 'each' because I have to sit next to him every day.
My cat and my dog are 'each' because they hate each other but are stuck in the same room.