Other forms: nieces
Your niece is the daughter of your brother or sister. My niece, his niece, a great-niece.
The male equivalent is nephew, and in ordinary use both cover a partner's siblings' children too. Her child is your great-niece or great-nephew. The word is pronounced neess and is one of the standard examples of the i-before-e rule. Note that many languages distinguish a brother's child from a sister's child and English does not, which is a real gap when translating older or anthropological texts.
1nounnieceThe daughter of your brother or sister.
“Her niece stayed with them every summer.”
niece is a relative.
Latin neptis meant granddaughter or niece, the feminine of nepos. Its Proto-Indo-European ancestor named a whole class of descendants, and English narrowed both words to one relationship each.
Latin
neptia
Old French
nece — niece, granddaughter
Middle English
nece — niece, granddaughter
English, today
niece
From Middle English nece (“niece, granddaughter”), from Old French nece (“niece, granddaughter”) (Modern French nièce (“niece”)) from Latin neptia, representing Latin neptis (“granddaughter”), from Proto-Indo-European néptih₂ (“granddaughter, niece”). a doublet of nift.
Etymology from Wiktionary, CC BY-SA