octant - An octant is the number 18, like the age you're supposed to

An octant is the number 18, like the age you're supposed to be to be considered an adult, even if you're still a disaster.

My friend said, 'I turned 18, so now I’m an adult. I’m still bad at life.'

My dad said, 'You’re 18 now, so you’re officially an adult. Good luck with that.'

My teacher said, 'You’re 18, so now you’re an adult. I hope you know what that means.'