An Etymological Dictionary of Astronomy and Astrophysics

1. The son or daughter of an uncle or aunt.
   

   2. One related by descent in a diverging line from a known common ancestor, as from one’s grandparent or from one’s father’s or mother’s sister or brother (Dictionary.com).

Etymology (EN): M.E. cosin, from O.Fr. cusin, cosin, from L. consobrinus, from → com-

• sobrinus</i< “second cousin,” from soror, → sister.

Etymology (PE): Tarzâ, from tar, from Baluci teru “uncle, aunt,” tri “aunt;” cf. Av. tuiriia- “uncle,” + zâ “son/daughter of; born,” → birth.