A "Subprime borrower" Is somebody who has a poor credit history or some other indication that would suggest that they might not be able to repay the mortgage-- they might default.

次级借款人"指的是,那些信用记录较差的借款人,或在其他方面显示,他们很可能无力偿还贷款,也就是说他们很可能违约

耶鲁公开课 - 金融市场课程节选

Subprime refers to mortgages, which is not the subject of today's lecture, but a subprime mortgage is a mortgage issued to a borrower who is not considered prime--not a good risk.

次贷指的是次级抵押贷款,这不属于今天的讨论范围之内,次级抵押贷款是发放给特殊借款人的,他们不是优质客户,也就是说风险较大

耶鲁公开课 - 金融市场课程节选