The term 'BIT OF HAIR DECORATION' can be solved by the crossword solution BEAD, which is a four-letter word. A BEAD is a small, decorative object that is often used to adorn hair. Beads come in a variety of shapes, sizes, and colors, and are usually made from materials such as glass, wood, metal, or plastic. They are often strung together to create intricate patterns and designs. Beads have been used for centuries as a form of decoration, and are still popular today.