Longman Dictionary of Contemporary English - precedence

~ n 1 take/have precedence over to be considered more important than someone or something else and therefore come or be done before them  (Saving the child's life took precedence over everything else.) 2 the relative importance of different things or people and the need to deal with the most important first, then the second most important, and so on  (in order of precedence)  (Arrange the tasks in order of precedence.)