|Origin:||, past participle of exigere 'to drive out, demand, measure', from agere 'to drive'|
to demand and get something from someone by using threats, force etc
exact something from somebody
I exacted a promise from Ros that she wouldn't say a word.
if someone exacts revenge, they punish a person who has harmed them:
Leonard was determined to exact revenge on his wife's killer.
if something exacts a high or a heavy price, it has a very bad effect on a person or on a situation:
The years of conflict have exacted a heavy price.