What does back out a big greaser mean?

back out a big greaser meaning in Urban Dictionary

A colloquial appearance, generally used in ( not limited by) Australia and similar/English speaking countries, for means of defecation. Usually connected with humans also humanoids, this expression is also be used to spell it out the defecation process of various other pets eg. your family pet. The same, somewhat less descriptive version may be the phrase back one away. Observe that your message greaser has actually an array of usage in other contexts.