1. To keep to:; SYN. stick with, follow.
2. When you are speaking or writing and you stick to a certain subject, you talk or write about that subject only.
3. When you stick to a certain belief, claim, policy, habit, plan, type of work, and so on, you continue as before, without change. Stick with is similar to stick to.

When you stick it to people, you deliberately try to tease, annoy, or embarrass them with an accusation, provocative statement, or difficult question.