Chiquilín / chiquilina
A kid, a teenager, a young person — still completely ordinary in Uruguay, where in Buenos Aires it has faded towards the nostalgic.
Related lesson: Uruguayan Spanish: A Survival Guide.
Hear it in context
Chiquilines, dejen de gritar que se escucha en toda la rambla.
Kids, stop shouting — you can be heard the whole length of the seafront.
Es una chiquilina de dieciséis, no le pidas tanto.
She's a sixteen-year-old, don't expect so much of her.
Desde chiquilín que juega en el mismo club.
He's played for the same club since he was a boy.
What It Actually Means
A chiquilín or chiquilina is a child or, more often, a young person somewhere in the teenage stretch. Uruguay has three live words for this — botija, gurí / gurisa and chiquilín — and they divide by age and by region rather than by meaning: botija is the Montevideo default and skews younger, gurí marks the interior and the north, and chiquilín reaches furthest up into adolescence and young adulthood.
Where It Comes From
Straightforward morphology for once: chico (small) gives chiquillo, and the affectionate suffix -ín gives chiquilín. No borrowing, no disputed story, no colonial jug. The word exists across a good deal of the Spanish-speaking world in one form or another; what varies is how alive it still is.
How Natives Use It
Everywhere and by everyone, most visibly as a vocative for a group — vamos, chiquilines from a coach, a teacher or an older relative. It is affectionate rather than diminishing when the age gap is real, and it is entirely ordinary in Uruguayan conversation. Argentina knows the word perfectly well, but in Buenos Aires it has drifted towards the wistful and the literary — the tango register — while pibe / piba does the everyday work. That gap in currency, not in meaning, is the Uruguayan part.
Common Pitfall
Watch the age arithmetic. Aimed at someone under about twenty-five it is warm; aimed sideways at a peer it means “you are too young to have an opinion about this”, which is a deliberate move and will be heard as one. And keep it out of anything written for work: the neutral words are joven, adolescente and chico/a, and a Uruguayan writing a report uses those, however many chiquilines they shouted at that morning.