Deal breaker thesaurus

Here are some synonyms for "deal breaker" from a thesaurus:

1. Showstopper: a problem or issue that prevents a project or plan from moving forward
2. Killer: a factor that can destroy or ruin something
3. Non-starter: a proposal or idea that is unacceptable or unworkable
4. Insurmountable obstacle: a problem that cannot be overcome or solved
5. Red flag: a warning sign or indication that something is wrong or unacceptable
6. Deal killer: a factor that can destroy or ruin a deal or agreement
7. Showstopper issue: a problem or issue that prevents a project or plan from moving forward
8. Fatal flaw: a weakness or defect that can cause something to fail or be unsuccessful
9. Non-negotiable: a condition or requirement that cannot be compromised or changed
10. Deal-killer clause: a provision or condition in a contract or agreement that can destroy or ruin the deal if not met.

Note that some of these words may have slightly different connotations or nuances, but they all generally convey the idea of a problem or issue that can prevent something from happening or being successful.