Final answer:
An antonym for the noun deadlock is "agreement" as it represents a situation of resolved conflict, opposed to a deadlock where no progress can be made.
Step-by-step explanation:
The antonym for the noun deadlock is agreement. A deadlock refers to a situation where no progress can be made due to a conflict, where two sides are equally matched and unable to defeat each other or make a move. It is often used to describe impasses in negotiations, where there is a complete absence of compromise or progress. Therefore, an agreement, which involves a mutually acceptable resolution to a conflict and signifies progress, serves as the exact opposite.