first cousin

/F ER1 S T K AH1 Z AH0 N/
noun
  1. 1

    A child of a parent's sibling; a nephew or niece of a parent; a child of one's uncle or aunt.

  2. 2

    A relative who has with the other person only two grandparents (maternal or paternal) in common, but parents are different.

Source: https://en.wiktionary.org/wiki/first%20cousin