Meaning

noun a person who slips or slides because of loss of traction

noun someone who races the luge

noun freshwater turtle of United States and South America; frequently raised commercially; some young sold as pets

originFrom slide + -er. The meaning "small hamburger" was originally used to describe onion-steamed small burgers at White Castle restaurants, formerly spelt "Slyder". Regarding the senses about control devices or widgets: physical sliders (potentiometers serving as rheostats) predate virtual ones (elements in graphical user interfaces), and the virtual ones are so named because their concept is the…

Etymology from Wiktionary, CC BY-SA 3.0