unilateral
🇺🇸
/ˌjuːnɪˈlætrəl/
🇬🇧
/ˌjuːnɪˈlætrəl/
done by one side only without asking others
The country made a unilateral decision without consulting its allies.
該國在沒有諮詢其盟友的情況下做出了單方面決定。