"cosign" in Chinese (Simplified)
共同签署担保
Definition
和另一个人一起在文件（通常是贷款或合同）上签字，承诺如果对方违约，你会负责还款或承担责任。
Usage Notes (Chinese (Simplified))
多用于金融或法律场合。'Cosign a loan' 指你为他人贷款作担保，要负责对方不能还款时的偿还责任。不是单纯见证签名，而是有财务责任。
Examples
My father agreed to cosign my apartment lease.
我爸爸同意为我的公寓租约**担保**。
You need someone to cosign if you want that loan.
如果你想要那笔贷款，你需要有人**共同签署**。
She asked her friend to cosign the contract with her.
她请朋友和她一起**担保**合同。
Don't cosign for someone unless you really trust them.
除非你真的信任对方，否则不要**担保**。
He refused to cosign the loan because it's a big responsibility.
他拒绝**担保**贷款，因为这是很大的责任。
My uncle agreed to cosign on my car, so I finally got the loan approved.
我叔叔同意为我的汽车**担保**，所以贷款终于获批了。