What's a butt-licker?

Someone recently named someone else a butt-licker in my presence.

Somehow, the term stuck. A butt-licker? Doesn’t sound like the person I want to be.

During the days that followed, I’d time and again watch myself, watch my words, and wonder whether what I was saying could be interpreted as butt-licking? Maybe it was butt-licking?

What is butt-licking, anyway? I’m guessing that throwing insincere compliments at someone to try to please would characterize as licking butt. But how about telling someone that you’re truly grateful for what he or she has given you? Is that butt-licking? Probably not.

Oh, well. Maybe I should just stop caring so much what other peole think.