What does Studentikoos mean?

"That's so studentikoos of you," she said when he did pre-drinks before the bar yet again.

Dutch student slang. This is a Dutch word. You will hear it a lot at Dutch universities, student associations and in student houses.

Studentikoos is anything that feels typically student: the traditions, the jokes, the slang, the cheap beer. This whole dictionary is a great example. The short version is stuko.