na-adjective
inefficient
Describes processes, methods, or systems that waste time, effort, or resources.
このやり方は非効率的だ。
This method is inefficient.
非効率的な会議を減らしたい。
I want to reduce inefficient meetings.
Compound of 非 (hi-, 'non-') + 効率的 (kōritsuteki, 'efficient').