The term 'It's Over a Buck' can be solved by the six-letter word 'ANTLER'. Antlers are the large and branching bony structures that grow on the heads of certain animals, such as deer, elk, and moose. They are made of bone and are shed and regrown each year. Antlers are used for defense and for competing with other males during mating season. They are also used in traditional medicine and as decorative items.