To obsess is to focus all of your attention on something, to become very focused on it. When you obsess about something, you are constantly thinking about it, and you are not able to focus on anything else.
Disputable means that something is open to debate or argument. This is usually because there is a lot of disagreement about what the correct answer is.
To dread something is to have a very strong negative feeling about it. You might dread going to school, because you know that you're going to have a lot of homework.
When someone has transitioned, they have gone through a process of changing their gender. This process can be difficult, but it is ultimately worth it.
Counterarguments are arguments that are designed to counteract the points that the other person is making. They are usually designed to show that the other person's argument is not valid.
To upend something is to cause it to fall over. If you upend a table, it will fall over and the dishes will get broken.
To sneeze is to interrupt the flow of air out of your nose by inhaling sharply. This causes you to cough, and sometimes to cry.