The term 'WIND UP OR WIND DOWN' is a phrase used to describe the process of winding something up or winding something down. It is often used in reference to winding a clock or winding a toy, but it can also be used to describe winding up or winding down an activity or task. The crossword solution for this term is END, which means to finish or conclude. This phrase is often used to signify the completion of a task or activity.