We don't have synonyms for deringer yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are deranged, ringer and derange.
(n) :
(dated, 1800s) Alternative form of derringer. [A type of very small, concealable pistol with one or two barrels, but without any loading system or magazine.]
(n) :
(dated, late 1800s) Alternative spelling of derringer. [A type of very small, concealable pistol with one or two barrels, but without any loading system or magazine.]
(n) :
(dated, 1800s) Alternative form of derringer. [A type of very small, concealable pistol with one or two barrels, but without any loading system or magazine.]
(n) :
(dated, late 1800s) Alternative spelling of derringer. [A type of very small, concealable pistol with one or two barrels, but without any loading system or magazine.]