casillero
/kasiˈʝeɾo/ · B2 · noun · m
locker
🗄️ casillero = casilla (small box/square) + -ero (holder) → a bank of little boxes
Casilla means small house or little square, from casa (house) + -illa (small). Add -ero, a suffix for the thing that holds or handles. A casillero is a set of tiny compartments: a pigeonhole for mail or a locker for belongings.