"PIE" . . . "?" . _:B734d79a7X3A195d1e795f5X3AX2D436 . "*sér‑o‑ [n.]" . "Etymology for: serum (la1500)" . "*sér‑o‑" . . _:B734d79a7X3A195d1e795f5X3AX2D436 "*sér‑o‑" .