Slips off can be replaced with various synonyms depending on the context it is being used. "Slides off" means to move smoothly and swiftly away from something. "Falls off" means to drop or descend from something, often unintentionally or due to a lack of adhesive. "Glides off" means to move away effortlessly and gracefully from something. "Loses grip" entails to unintentionally release contact with a surface. "Escapes" means to break away or flee, while "disengages" denotes to detach or become disentangled. "Squirms out" means to wriggle one's way out of something, while "runs away" means to depart hastily and without permission.