/ ˌjuːnɪˈlætrəl; NAmE / adjective
done by one member of a group or an organization without the agreement of the other members :
a unilateral decision
a unilateral declaration of independence
They were forced to take unilateral action.
They had campaigned vigorously for unilateral nuclear disarmament (= when one country gets rid of its nuclear weapons without waiting for other countries to do the same) .
—compare bilateral , multilateral , trilateral
► uni·lat·eral·ly / -rəli; NAmE / adverb