A standard mug of steamed, frothed soy (or other non-dairy) milk.
Like a babyccino but for teenagers.
Mum (ordering at coffee shop): I’ll have a teenyccino and a latte.
Server: A what?
Mum: oh sorry, a cup of steamed frothy soy milk
Server: like a babyccino
Mum: but bigger, and soy
Server: got it - teenyccino - I like it.