step to

verb3

1. •
   (slang) To challenge, confront or fight (with someone).

   • Walter was angry, so he stepped to Bill.
2. •
   (slang) To meet a challenge or confront (someone).

   • I couldn't let that insult go unchallenged, so I stepped to him.
3. •
   To begin (a project or plan) quickly or urgently.

   • We got permission, so you had better step to it.