Merriam-Webster's Collegiate® Dictionary, 11th Edition
SLIPPER
I. adjective
Etymology: Middle English, from Old English slipor; akin to Middle Low German slipper slippery, slippen to slip Date: before 12th century slippery ,
II. noun
Etymology: Middle English, from slippen to slip
Date: 15th century
a light low-cut shoe that is easily slipped on the foot, slippered adjective