shape up

Verb

shape up (third-person singular simple present shapes up, present participle shaping up, simple past and past participle shaped up)

1. (idiomatic, intransitive) To improve; to correct one's bad habits or behavior.
   • He'd better shape up soon, or he'll fail the class.
   • You better shape up
     'Cause I need a man
     And my heart is set on you1978, John Farrar, “You're the One That I Want”, performed by Olivia Newton-John and John Travolta

   Synonyms:

   improve, pull one's finger out, pull one's socks up

2. (idiomatic, intransitive) To take shape; to transform into or become.
   • The fog has vanished and it's shaping up to be a beautiful day.
   • Pretty good. A full refrigerator! I can see this afternoon is shaping up just great.1983, 02:04:00 from the start, in The Right Stuff

   Synonyms:

   become, turn into, turn out to be

3. (intransitive, slang) To gesture or posture threateningly; to approach as if to fight; to pose to intimidate.

   Synonyms:

   bridge up