means A soft, light, low shoe meant to be slipped on easily, usually worn indoors for comfort.

from From the verb 'slip' plus the agent suffix '-er' — literally a thing you slip onto the foot. English has called soft indoor shoes 'slippers' since the late Middle Ages, built straightforwardly from 'slip,' an old Germanic root for sliding or moving smoothly, a cousin of words in Dutch and German for the same gliding motion. The name simply describes the trick: no buckles, no laces, just foot in, foot out.