你二大爷的三姥爷的四舅妈
[nĭ èr dà yé de sān lăo yé de sì jiù mā]
It is quite a comical way to describe someone by a convoluted family tree connection which translates roughly to 'your great-uncle's great-grandpa's aunt.' The humor lies in the complexity of relations described, hinting playfulness around understanding familial connections.