flatiron noun 5adjective 1forms 1 noun5 •A simple iron (for pressing laundry) which is heated on a stove. •A pair of metal tongs with heated ceramic plates used for straightening hair. •Ellipsis of flat iron steak. •A steeply sloping triangular landform created by the differential erosion of a steeply dipping, erosion-resistant layer of rock overlying softer strata. •a quadrilateral with two parallel sides, one of which is very short, and whose non-parallel sides are longer than either parallel side. adjective1 •Having a flatiron shape.The street down which Warwick had come intersected Front Street at a sharp angle in front of the old hotel, forming a sort of flatiron block at the junction, known as Liberty Point — 1900 formsflatirons