The phrase "justly deserved" can be used to describe a situation where someone has rightly earned something through their actions or behavior. Some synonyms for "justly deserved" include "rightfully earned", "deservedly obtained", "fairly warranted", "legitimately merited", and "reasonably earned". These words can be used interchangeably to convey the same message of deservingness. It is important to use these words accurately and appropriately to accurately convey the intended meaning of the sentence. So, whether it's a promotion at work or a reward for good behavior, using any of these synonyms for "justly deserved" will help to emphasize the righteousness and justice of the situation.