A flop will be defined here as a movie that does not recoup it's production costs 3 months after it's release date.

I will be primarily using boxofficemojo.com and https://www.the-numbers.com/movie/budgets/all to make this determination. If the answer is not obvious based on these two sites, especially with regard to production costs I will use widely reported numbers. If there is ambiguity regarding the production costs due to conflicting reporting that puts the profitability in doubt the answer will resolve to "Yes". Any movie that barely breaks even is in effect a flop.

When adding movies please include the release date in the answer.