By right is an expression that means something is justified or has a rightful claim. There are several synonyms for this phrase, including rightfully, justifiably, legitimately, and understandably. All of these words convey the idea that there is a valid reason for something to be happening or a situation to exist. Additionally, terms like deservedly, rightfully so, and by definition can also be used to express the same sentiment. It's important to understand the context of the situation when selecting a synonym for by right to ensure that the correct meaning is conveyed.