Other hyponyms of youngster include
bairn,
buster,
changeling,
child prodigy,
infant prodigy,
wonder child,
foster-child,
foster child,
imp,
monkey,
rapscallion,
rascal,
scalawag,
scallywag,
scamp,
kiddie,
kiddy,
orphan,
peanut,
picaninny,
piccaninny,
pickaninny,
poster child,
kindergartener,
kindergartner,
preschooler,
silly,
sprog,
bambino,
toddler,
tot,
yearling,
urchin,
street child,
waif.