The adverb consistently describes something that's done the same way for a long time. If your mom consistently forgets to add sugar when she's baking cookies, it means you can count on inedible cookies.
When something happens again and again, it happens consistently. In fact, the Latin root is consistentem, meaning "standing still." Consistently is most often used to describe something you can depend on, like consistently getting hungry right before lunch, or your dog consistently appearing by your side to cheer you up whenever you're feeling sad.