'step up' definitions:

Definition of 'step up'

From: WordNet
verb
Increase in extent or intensity; "The Allies escalated the bombing" [syn: escalate, intensify, step up] [ant: de-escalate, step down, weaken]
verb
Speed up; "let's rev up production" [syn: rev up, step up]
verb
Make oneself visible; take action; "Young people should step to the fore and help their peers" [syn: come to the fore, step forward, come forward, step up, step to the fore, come out]