buzón
/buˈθon/ · B2 · noun · m
mailbox
📮📬 Sounds like boo-THON: drop a letter in, and the box says boo!
The -ón ending is the Spanish suffix that makes things big, as in cajón (drawer) and portón (gate). A buzón is a big slot that swallows letters, which is also why it can mean big mouth.