A stiletto heel (AmE: spike heel) is a long, thin heel foun on some boots and shoes, usually for women. It is named after the stiletto dagger, the phrase being first recorded in the early 1930s. Stiletto heels may vary in length from 2.54 centimetres (1 inch) up 20.32 cm (8 inches), and are sometimes defined as having a diameter at the ground of less than 1 cm (half an inch). Such heels shorter than 5 cm are called kitten heels.