The phrase "most defeatist" implies a negative and hopeless attitude towards a particular situation. Some synonyms for this phrase could include "pessimistic," "fatalistic," "despairing," "doom and gloom," "negative," and "cynical." These words share a common feeling of resignation and lack of faith in a positive outcome. Other similar phrases that could be used in place of "most defeatist" might include "the worst-case scenario mindset," "defeatism at its peak," or "a sense of hopelessness and futility." Regardless of the word choice, these descriptors all convey a sense of negativity and a lack of possibility for success.