step up in WordNet English dictionary

1. make oneself visible; take action
   "Young people should step to the fore and help their peers"
   come to the fore  step forward  come forward  step up  step to the fore  come out 
   
2. increase in extent or intensity
   "The Allies escalated the bombing"
   escalate  intensify  step up 
   
3. speed up
   "let's rev up production"
   rev up  step up 
   

step up in English Wiktionary