family custom; family tradition
Refers to a custom or practice passed down within a particular family. Somewhat formal and not an everyday word; 家の習慣 (ie no shūkan) is more common in casual speech.
This family custom has been passed down since the Edo period.
Following the family tradition, relatives always gather for New Year's.
Compound of 家 (ie, 'house, family') and 例 (rei, 'example, precedent'). The exact historical derivation is uncertain, but the word literally suggests 'family precedent'.