The term SLUGGISH MAMMAL can be solved by the crossword solution SLOTH, which is a five-letter word. Sloths are slow-moving mammals found in Central and South America. They are known for their low energy levels and slow movements, which is why they are considered to be sluggish mammals. Sloths are arboreal animals, meaning they spend most of their lives in trees. They are also nocturnal animals, meaning they are active at night.