Any theory of why my surname has such a strange translation?

my last name is the Czech word for "slush." also, to similar things such as slop, swill, slurry, slosh, mush, dishwater, etc....So i understand that people 4-5 centuries ago or so added last names to their first names based on things such as appearance, surroundings, nickname, or their occupation......but any idea of why someone would choose, or be picked the name "SLUSH?"