Square Academic Cap

The square academic cap, graduate cap, or mortarboard (because of its similarity in appearance to the hawk used by bricklayers to hold mortar) or Oxford cap, is an item of academic head dress consisting of a horizontal square board fixed upon a skull-cap, with a tassel attached to the center. In the UK and the US, it is commonly referred to informally in conjunction with an academic gown worn as a cap and gown. It is also often termed a square, trencher, or corner-cap in Australia. The adjective academical is also used. In the US and UK, it is usually referred to more generically as a mortarboard, or (in the U.S.) simply cap.

The cap, together with the gown and (sometimes) a hood, now form the customary uniform of a university graduate, in many parts of the world, following a British model.