To pester someone means to annoy or bother them repeatedly.
When people pester each other, they might call, text, or email over and over again until the other person gives in. This can happen with friends asking for favors, family members reminding you of chores, or even salespeople trying to convince you to buy something. Pests aren't necessarily mean-spirited, but their persistence can be frustrating. You might say, "Stop pestering me, I'll get it done eventually!"
To bother, harass, or annoy persistently.
