register

If you register someone or something, you put their name on a list.

Example: I haven't registered for September classes yet.

If you register a complaint, protest, etc. you make your opinion known formally.

If something doesn't register, you don't notice it.

Example: I knew I had something else on, but I guess it just didn't register when I made the appointment.

If a measuring instrument registers a value, it shows that value.

Example: The thermometer registered 42.5°.

A register is an official list of names.

Example: On voting day, I found my name was not on the register and I couldn't vote.