white lie, a
An untruth told to spare feelings or from politeness, as in She asked if I liked her dress, and of course I told a white lie. This term uses white in the sense of "harmless." [First half of 1700s]
a white lie
If you tell a white lie, you say something which is untrue, often in order to protect someone or to avoid upsetting someone. I said she looked nice, thinking it kinder to tell a white lie. I believe that this is a case where a little white lie is really more appropriate than the truth.
a white ˈliea small or harmless lie that you tell to avoid hurting somebody: When she asked me if I liked her new dress I had to tell a white lie. I thought it looked awful, but I couldn’t say so!
white lie, a
A fib told out of politeness, to spare feelings, or for a similar reason. The term is intended to distinguish between such a fib and a black lie, considered heinous dishonesty. A 1741 issue of Gentleman’s Magazine stated, “A certain Lady of the highest Quality . . . made a judicious distinction between a white Lie and a black Lie. A white Lie is That which is not intended to injure any Body in his Fortune, Interest, or Reputation, but only to gratify a garrulous Disposition, and the Itch of amusing People by telling them wonderful Stories.” However, warned William Paley in Moral Philosophy (1785), “White lies always introduce others of a darker complexion.”
See also: white