The term 'stick fast' can be broken down into two crossword solutions: MIRE (4 letters) and ADHERE (6 letters). MIRE is a verb meaning to become stuck in mud or dirt, while ADHERE is a verb meaning to stick firmly to something. Both words are used to describe the action of sticking fast, which is when an object becomes stuck in place due to adhesion or suction. This phenomenon is often seen in nature, such as when a gecko's feet stick to a wall or when a spider web catches an insect.