The phrase "constant struggle" refers to a situation or condition in which someone is constantly facing difficulties, challenges and obstacles. It implies that there is an ongoing battle or fight against something, whether it be internal or external forces, and that progress is slow or difficult due to the constant barriers that must be overcome. The phrase can also suggest that the struggle is never-ending, with no clear resolution in sight. Overall, "constant struggle" conveys a sense of hardship, difficulty and perseverance in the face of adversity.