A reinsurer is the company — sometimes, in careful legal talk, the party — that takes on that shared risk. You buy car insurance from company A. A then pays company B to cover part of A’s losses if too many claims come in at once. B is the reinsurer. The first company is still your insurer; the reinsurer sits behind it, and you may never deal with them at all. Though actually, the -er does not mean “someone who buys insurance again.” It means the specialist who provides reinsurance. Same business idea as reinsure and reinsurance, but this word names the firm that accepts the shared risk.

再保險人、再保公司（承接別家保險公司轉來之風險的那一方）