Partition under income tax requires actual physical division of property; mere status change or decree is insufficient. Partition for income tax purposes requires actual physical division of the property where divisible, or where not divisible, division to the extent the property admits; mere severance of status, court decrees, or agreements do not constitute partition for tax assessment unless they produce physical division. The special tax meaning of partition does not apply where the family was never assessed as a Hindu undivided family.