noun Older Use: Often Offensive.
(used to emphasize the truth of a statement).
Also, honest injun.
Americanism; see Injun
Usage noteHonest Injun
uses an informal, nonstandard spelling of Indian.
Probably first used by Mark Twain, this expression is now dated and often perceived as insulting to or by American Indians. Though it came to mean “honestly or truly,” it may have had its origin in the contrary perception that Indians on the American frontier were not considered honest or trustworthy until they had proven themselves, for example, as scouts. See also Indian.