"Runs against" is a phrase that refers to an opposition or contradiction to a particular concept or idea. There are numerous synonyms for this term such as contradicts, opposes, challenges, defies, conflicts, and contests. Each of these words denotes a different level of opposition and can be used in varying contexts. For example, "contradict" and "oppose" both suggest an outright rejection of an idea, while "challenges" and "defies" tend to imply a more confrontational approach. On the other hand, "conflicts" and "contests" may denote a competitive or combative nature to the opposition. Therefore, depending on the context, one may opt to use one of these synonyms interchangeably with "runs against".