The crossword solutions for the term MAD. AND LEX. are AVES, which stands for Aves, the Latin word for birds. Aves is a large and diverse group of animals that includes all species of birds, from the smallest hummingbird to the largest ostrich. They are found in almost every habitat on Earth, from the Arctic tundra to the tropical rainforest. Birds have adapted to their environment in many ways, such as developing feathers for flight and specialized beaks for feeding.