The term 'LESS FORMAL ALTERNATIVE TO A TOGA' can be answered with the 5-letter word 'TUNIC'. A TUNIC is a type of garment that has been worn since ancient times. It is typically a loose-fitting, knee-length garment with long sleeves and a round neckline. It is often made of lightweight fabrics such as cotton or linen. Tunics are often seen as a less formal alternative to a toga, which is a draped garment worn in Ancient Rome.