Meaningless; lacking significance, purpose, or value; pointless.
この議論は結論が出ず、ただ無意義に時間が過ぎた。
The discussion reached no conclusion and time just passed meaninglessly.
その説明は私には無意義に聞こえた。
That explanation sounded meaningless to me.
無意義な作業を続けるのはつらい。
It's hard to continue doing meaningless work.