The bank sent me an email informing me that I had a pre-approved loan limit.

pre-approved 是由前缀 pre-（表示“预先”）和动词 approve（批准）的过去分词 approved 组合而成，字面意思是“预先批准的”，指贷款额度已经预先通过审核，不需要再次申请审批。