The term "counter signing" implies that a signature is being placed on a document as an additional confirmation or validation. Antonyms for this phrase would include actions such as ignoring, reject, disavow, or spurning a signature. Rather than affirming a signature with a counter signature, these actions break the chain of validation and indicate a lack of agreement or approval. Another antonym could be to sign in a conflicting manner, such as signing with a false or conflicting identity. Ultimately, counter signing bears the idea of two signatures acting in tandem, whereas these antonyms indicate a deliberate separation between the signature and agreement.