shaping up or shipping out

Verb

shape up or ship out (third-person singular simple present shapes up or ships out, present participle shaping up or shipping out, simple past and past participle shaped up or shipped out)

1. (idiomatic) To either improve one's behavior or else be required to leave; to either improve one's performance in an activity or else withdraw from that activity completely.
   • Portions of those letters quoted by Bruccoli indicate that though Hemingway could be sympathetic, he used a lot of ink telling Fitzgerald to shape up or ship out.1978 April 3, R. Z. Sheppard, “The Far Side of Friendship (review of Scott and Ernest by Matthew J. Bruccoli)”, in Time