The term 'cone head' can refer to a variety of things, but in this case it is referring to a type of tree. The crossword solutions for the term are ROD (3 letters), FIRS (4 letters), PINE (4 letters), and SNO (3 letters). ROD is likely referring to a ROD-shaped cone, which is a type of cone that is shaped like a cylinder. Firs are a type of evergreen tree, and PINE trees are also a type of evergreen tree. Sno is likely referring to snow, which is often associated with coniferous trees such as firs and pines.