tautology

n.无谓的重复；重言；累赘

To say that something is'adequate enough'is a tautology. 说某样东西“足够够用了”就是一个同义反复。

To create man was a fine and original idea;but to add the sheep was a tautology. 创造人类，是一则美好而又富于独创性的想法，但加上羔羊则未免多余。