The adage “use it or lose it” applies to the word “desuetude.” It comes from the Latin “desuescere,” meaning “to become unaccustomed.” In English it implies something has fallen out of use, either by time or lack of interest. Many appliances fall into desuetude when newer models come out. Advancing technology also plays a large role — for example, dial-up internet is in desuetude because cable and fiber internet are capable of much greater speeds.