the granddaughter of one's brother or sister; great-niece
grandniece in American English
(ˈɡrænˌnis, ˈɡrænd-)
noun
a daughter of one's nephew or niece
Word origin
[1820–30; grand- + niece]This word is first recorded in the period 1820–30. Other words that entered Englishat around the same time include: acetate, analogue, blouse, boomerang, morphology