Which type of lamp is powered up by a ballast?

Which word names both a type of far-out 1960s music and the class of drugs that inspired it? Which word names both a type of fish and to sit on an elevated spot? Which type of hammer, with a rounded head, is used for shaping metal? What is an Italian countess called, like the "Barefoot" one in the 1954 Ava Gardner film? Which large snake may be reticulated? Which word names both a type of lizard and a computer screen? In health insurance, what does HMO stand for? Which orange-fleshed melon is named after a former papal estate near Rome?