The term 'ZOO BUILDING' can be broken down into two words, 'ZOO' and 'BUILDING'. The first word, 'ZOO', is a facility in which animals are kept and exhibited to the public. The second word, 'BUILDING', refers to a structure that is constructed for a specific purpose. The crossword solution for this term is 'AVIARY', which is a large enclosure used to house birds. An AVIARY typically contains multiple levels of perches, nesting boxes, and other features to provide a safe and comfortable environment for the birds.