unnecessaryWiktionary 原文中文来自 ECDICTadj.不必要的构词拆分un-前缀(added to adjectives or past participles) not · (added to nouns) lack of+necessary词根/词干词源说明From un- + necessary.释义（英文）形容词 AdjectiveNot needed or necessary.Done in addition to requirements; unrequired.词族派生词（3）unnecessariesunnecessarilyunnecessariness