The phrase "take liberty" is often used to describe situations where someone has acted without permission or taken an unwarranted action. Synonyms for "take liberty" include "assume," "presume," "overstep," "trespass," "encroach," "infringe," "violate," and "transgress." These words can be used to describe situations where someone has gone beyond what is acceptable or expected. For example, if someone assumes that they can speak on behalf of a group without asking for permission, that would be taking a liberty. Using synonyms can help to convey a sense of the severity of the action and the potential consequences.