According to Wikipedia a skyscraper is a tall, continuously habitable building. There is no official definition or height above which a building may clearly be classified as a skyscraper. Most cities define the term empirically; even a building of 80 meters (262 feet) may be considered a skyscraper if it protrudes above its built environment and changes the overall skyline.
The term was first applied to buildings in the late 19th century as a result of public amazement at the tall buildings being built in Chicago and New York City.[1] The first skyscraper was for many years thought to be the Home Insurance Building built in Chicago, Illinois in 1885. More recent arguments point to New York’s seven floor Equitable Life Assurance Building built in 1870 and it was arguably the first office building built using a kind of skeletal frame but it depends on what factors are chosen and even the scholars making the argument find it academic.[2]
The structural definition of the word skyscraper was refined later by architectural historians, based on engineering developments of the 1880s that had enabled construction of tall multi-storey buildings. This definition was based on the steel skeleton—-as opposed to constructions of load-bearing masonry, which passed their practical limit in 1891 with Chicago’s Monadnock Building.