Just be careful with that stuff.

1. "Подлизываться" - is ok word, which stands for "to flatter"
подлизываться — Викисловарь

2. "Лизать зад" - rude, but commonly used by russians (to lick someones anus; perform any dirty work, to overstep over own pride in order to get close to someone or some possibilities).

Same root, different "power".