noun
lineage; line; unification; all of you
A somewhat formal or old-fashioned noun. Can refer to a family line, the act of unifying, or a collective address meaning 'everyone'. The 'all of you' sense is often used in formal announcements or letters.
この家系は一統が長く続いている。
This family line has continued for a long time.
ご一統様のご健康
I pray for the health of all of you (your family/group).