unascertainableWiktionary 原文构词拆分un-前缀(added to adjectives or past participles) not · (added to nouns) lack of+ascertainable词根/词干词源说明From un- + ascertainable.释义（英文）形容词 AdjectiveThat cannot be ascertained; uncertain, unable to be determined or discovered.词族派生词（1）unascertainably