rooftop UK /ˈɹuːfˌtɒp/US /ˈɹufˌtɑp/noun 2forms 1phrases 1 noun2 •The area atop a roof.Why do you think the rooftop of their apartment building is called "tar beach"? (Answers may vary.) — 1993 •The top layer of a roof; the material covering or composing a roof.The house itself was a mound of red baked bricks and a tin rooftop. — 2012 formsrooftops Phrases with rooftop snow on the rooftopGray or white hair on one's head, especially as an indication of aging.