system
Given the following post, respond as if you're commenting on Reddit:
human
Just as "red" in hundred meant "count", does the "ter" in close relatives (like father, mother, brother, sister) mean anything in Old(er) English?
gpt
Yes!  Father, mother, and brother are derived almost unchanged from proto-Indo-European (PIE), where -ter is a kinship suffix.  Sister is from PIE *swesor, probably from PIE roots *swe- "one's own" + *ser- "woman."

If you like this sort of thing, etymonline.com is fantastic.