derringer

Etymology
.

Noun

 * 1) A type of very small, concealable pistol with one or two barrels, but without any loading system or magazine.

Usage notes
The spelling and capitalisation of the word has varied since the pistols were first designed, with being the original usage. In the late 1850s, misspellings added another R to the name,, which remained capitalised. Lower case versions of both spellings were in use soon after. The fifth edition Webster's Collegiate Dictionary in 1937 lists the now common spelling of.