ADJ [oft ADJ to-infinitive]不充分的;不足的;缺乏的 Something that is insufficient is not large enough in amount or degree for a particular purpose. 不充分的;不足的;缺乏的 [formal] [Also + for]
He decided there was insufficient evidence to justify criminal proceedings.
他认定证据不充分无法提起刑事诉讼。
These efforts were insufficient to contain the burgeoning crisis.