sky·scrap·er Audio Help /ˈskaɪˌskreɪpər/ Pronunciation Key - Show Spelled Pronunciation[skahy-skrey-per] Pronunciation Key - Show IPA Pronunciation
–noun 1. a relatively tall building of many stories, esp. one for office or commercial use.
2. Architecture. a building of exceptional height completely supported by a framework, as of girders, from which the walls are suspended, as opposed to a building supported by load-bearing walls.
I tend to go by the general Emporis definition - a continuously occupied building of at least 12 stories or 35 meters.