RhymeZone: thunderbox definitions

Definitions of thunderbox:

noun: (slang) A chamber pot enclosed in a box; a portable commode.
noun: (by extension, chiefly Australia, Britain, slang) Any lavatory or toilet, especially a rudimentary outdoor latrine or toilet, or an outhouse.
noun: (theater) A box of metal balls which is shaken to create a thunder sound effect.
noun: (military, obsolete) A blunderbuss; also, a cannon.

(Definitions from Wiktionary)