according to the rules; in a way that is considered to be acceptable and appropriate按照规则；公正地；公平合理地◆He claims they didn't play fair in winning the contract (= they did sth dishonest in order to get it).他声称他们是以不正当手段赢得合同的。●set fair (to do sth/for sth) () having the necessary qualities or conditions to succeed有成功的素质；具备成功的条件◆The company looks set fair for growth.这家公司看起来具备了发展的条件。