wife's family; wife's parents' home
Refers to the family or home of one's wife, especially from the husband's perspective. Often used in contexts of marriage, visits, or support from the wife's side.
彼は正月に里方へ挨拶に行った。
He went to greet his wife's family at New Year's.
出産後、妻は
After giving birth, his wife stayed at her parents' home for a while.
Compound of 里 (sato, 'village, hometown') and 方 (kata, 'direction, side'). The exact historical derivation is uncertain, but it naturally came to mean the wife's family side.