When it comes to describing a difficult task, there are countless synonyms available to express the various degrees of complexity and hardship. Some common synonyms for difficult task include challenging task, arduous task, demanding task, taxing task, grueling task, laborious task, formidable task, complex task, intricate task, and onerous task. These words convey a sense of struggle, effort, and difficulty, making them ideal for describing tasks that require significant diligence, expertise, and perseverance. Ultimately, the choice of synonym depends on the level and nature of the task's difficulty, as well as the specific context and audience it is being described to.