Then if it becomes known that they both have been guilty of a sin, two others shall stand up in their place from among those who have a claim against them, the two nearest in kin; so they two should swear by Allah: Certainly our testimony is truer than the testimony of those two, and we have not exceeded the limit, for then most surely we should be of the unjust.
Meaning:-
kin : relatives, relations, family (members),
Testimony: witness, Eye witness, evidence.