1North American Sign (a loan or lease) jointly with another person in order to guarantee payment.‘you may have to get someone to co-sign your loan if you do not have a previous credit history’
- ‘see if your parents will co-sign for you’
2North American Sign (a document) jointly with another or others.
- ‘he is joined by a host of musical artists who co-signed an open letter to the US Congress’
- 2.1informal Endorse or agree with.
- ‘I co-sign all the advice on this thread’
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