The Right Name for the Right Cousin

Conversation on the subject of who is related to whom often bogs down over terminology, particularly when it comes to defining cousins.

Your FIRST COUSIN, of course, is your parent’s brother’s (or sister’s) child. However, the first cousin’s child is not your second cousin, but your FIRST COUSIN ONCE REMOVED. The child of the first cousin once removed is your FIRST COUSIN TWICE REMOVED, and his child is your FIRST COUSIN THREE TIMES REMOVED.

Your SECOND COUSIN is you grandparents’ brother’s (or sister’s) grandchild. That second cousin’s child is your SECOND COUSIN ONCE REMOVED, and his child is your SECOND COUSIN TWICE REMOVED, and so on.

And your THIRD COUSIN? It’s your great-grandparent’s brother’s (or sister’s) great-grandchild. The third cousin’s child is your THIRD COUSIN ONCE REMOVED, his child is your THIRD COUSIN TWICE REMOVED.

Some other occasionally misunderstood terms:

  • Siblings have parents in common. Brothers and sisters are siblings.
  • Grandnephew (or grandniece) : the grandchild of your brother or sister.
  • Great-aunt (or great-uncle) : the sister (or brother) of you grandparent.
  • Great-grandaunt (or great-granduncle) : the sister or brother of your great-grandparents.
  • Stepfather (or stepmother) : the husband or wife of your parent by a subsequent marriage.
  • Stepchild : the child of your husband or wife by a former marriage.
  • Stepsister (or stepbrother) : the child of your stepfather or stepmother.
  • Half sister (or half brother) : the child or your parent and step-parent.
  • In-laws : your connections by the law of marriage (as distinct from relatives by blood); in particular, your husband’s or wife’s relatives and your own brother’s wife or sister’s husband.
  • Ancestor : the person from whom you descend “directly”, such as a grandparent or great-grandparent.
  • Descendant : the person who descends “directly” from you, such as a grandson or great-granddaughter.
  • Lineal relations : those in the “direct” line of ascent or descent, such as a grandfather or granddaughter.
  • Collateral relations : those relatives who are “linked” by a common ancestor, such as aunts, uncles, and cousins.