Insufficient or inadequate; not enough in amount or degree to meet requirements or expectations.
準備が不十分だったため、発表で失敗してしまった。
Because my preparation was insufficient, I failed in the presentation.
情報が不十分なので結論を出せない。
We can't draw a conclusion because the information is inadequate.
対策はまだ不十分だ。もっと検討が必要だ。
The measures are still inadequate. More consideration is needed.