like a greased pig

like a greased pig

mainly AMERICAN
If someone is like a greased pig, they move very fast and nobody can catch them or stop them. He slid past her like a greased pig. Note: This may come from a fairground competition which was popular in the past, in which a piglet that had been covered in grease was let loose and the person who caught it won a prize.
See also: grease, like, pig