flat iron

noun

1. 1.A tough cut of beef from the shoulder of the steer.
2. 2.A simple iron (for pressing laundry) which is heated on a stove.
3. 3.A pair of metal tongs with heated ceramic plates used for straightening hair.
4. 4.(especially referring to the shape of a building) a quadrilateral with two parallel sides, one of which is very short, and whose non-parallel sides are longer than either parallel side.
5. 5.A steeply sloping triangular landform created by the differential erosion of a steeply dipping, erosion-resistant layer of rock overlying softer strata.