The term 'Hogwarts Stick' is a reference to the magical WAND used by Harry Potter in the popular book series. The crossword solution for this term is 'WAND, ' which is a four-letter word. A WAND is a thin, hand-held stick that is used by witches and wizards to cast spells and perform other magical feats. In the Harry Potter universe, wands are made from a variety of materials and are chosen by the witch or wizard based on their individual magical abilities.