A child of a first cousin of one's parent.

Roget 11: consanguinity, relationship, kindred, blood; parentage etc. (paternity) 166; filiation^†, affiliation; lineage, agnation^†, connection, alliance; family connection, family tie; ties of blood; nepotism.    kinsman, kinfolk; kith and kin; relation, relative; connection; sibling, sib; next of kin; uncle, aunt, nephew, niece; cousin, cousin-german^†; first cousin, second cousin; cousin once removed, cousin twice removed; etc. near relation, distant relation; brother, sister, one's own flesh and blood.    family, fraternity; brotherhood, sisterhood, cousinhood^†.    race, stock, generation; sept etc. 166; stirps, side; strain; breed, clan, tribe, nation.    ... show more

Dutch: achterneef