uselessly; in vain; pointlessly
Describes an action that yields no meaningful result; often used in formal or literary contexts. Can imply idleness or futility.
I ended up spending time pointlessly.
いたずらに争うのはやめよう。
Let's stop fighting in vain.
He spent his time uselessly and accomplished nothing.
No matter how much they argued pointlessly, no conclusion was reached.
Rather than fearing the future needlessly, let's do what we can now.