A group of trout is commonly called a Hover. Other collective nouns you may see include Spawn and Run.
A collective noun for trout is a "school." As diverse species of freshwater fish found worldwide, trout live in schools and exhibit exceptional coordination and cooperation in their natural habitats, such as streams, lakes, and rivers. Within these groups, trout swim together, often forming tight formations, for various purposes, including protection against predators, finding food, and migrating. The school is essential for the survival and efficient functioning of the trout community. These close-knit gatherings of trout exemplify the harmony and unity found in nature, as individuals work together for the greater benefit of the group.
Known collective nouns for Trout include: