To eat or drink something quickly or greedily. He snarfed down his lunch in just a few minutes before heading back to work.
To acquire something, especially in a greedy or eager manner. She managed to snarf the last piece of cake before anyone else could get to it.
Computing slang: to copy or download (data or a file) quickly, often without the owner's permission. The hacker snarfed the password file before anyone noticed.