Значение идиомы shape up or ship out

[shape up or ship out] {v. phr.}, {informal} To either improveone’s disposition or behavior, or quit or leave.

When Paulneglected to carry out his part of the research work that ProfessorBrown had assigned him with for the fifth time, the professor cried,”Shape up, or ship out, Paul. I have lost my patience with you!”