1. To begin violently or aggressively eating something. I was so hungry that I tore into the cheap hamburger like it was the most delicious thing I'd ever eaten. I looked away when the wolves began to tear into their prey.

2. To criticize or reproach someone or something in a severe and merciless manner. The boss tore into me for how I bungled the Jefferson account. I can hear Mom tearing into Dad again about his gambling.