The antonyms for the phrase "written promises" can be described in varying ways, depending on the context in which it is used. Some of the synonyms for the word "promise" include "break," "betray," "abandon," "disappoint," and "dishonor," among others.
Therefore, the antonyms for "written promises" can include verbal agreements, verbal disagreements, spoken commitments, informal pledges, and general agreements that do not involve written documentation. These antonyms imply a lack of commitment or a non-binding nature of the agreement, indicating a lack of seriousness compared to written promises.
In conclusion, while written promises are regarded as legally binding and enforceable contracts, their antonyms in the form of verbal agreements hold less weight, indicating a less serious tone of the commitment.