not fulfilling or not expected to achieve the intended purpose or desired outcome
无用的,无效的
-
a piece of useless knowledge .无用的知识
-
we tried to pacify him but it was useless .我们试着抚慰他,但一切都是徒劳的。
〈非正式〉 (特定活动或领域中)无能力的;没有技能的
-
he was useless at football .他不会踢足球。