Wow! That salesman is still talking to my mom. How persistent!
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means sticky and the verb vocab version is to be sticky. It can also mean to persevere, because if you're being sticky towards the situation, not giving up and not letting go. You're totally persevering by sticking around.
Will I give up? I'll nevah (ねば) give up! I'll also nevah unstick from you.