Consistent is about staying the same in behavior or results across different times or situations. The strongest definition here is the idea of constantly acting or behaving the same way, because that directly captures the everyday sense of reliability and uniformity that “consistent” conveys. If someone is consistent, you can predict how they’ll respond or perform next time because their actions don’t vary much from occasion to occasion. Regular is related, but it emphasizes frequency or routine rather than uniformity of action across moments. Not changing over time describes stability, which is part of being consistent but misses the explicit notion of repeated, similar behavior. Loyal is about allegiance to people or a cause, not about consistent behavior or performance.