Stubborn effort can be defined as the unrelenting and determined drive towards a certain goal or objective. Some synonyms for stubborn effort include perseverance, tenacity, grit, determination, willpower, and hard work. Tenacity and perseverance refer to the unwavering persistence in spite of obstacles or setbacks. Grit is defined as the sustained effort and resilience displayed in the face of challenges. Determination emphasizes the willpower and resolve needed to achieve a particular aim, while willpower itself taps into an individual's inner strength. Hard work refers to the consistent and dedicated effort required to achieve success. These synonyms all highlight the importance of perseverance and resilience in achieving one's goals.