The phrase "be seized of" means to have possession or control over something. There are a multitude of synonyms that can be used in place of this phrase, including "to own," "to possess," "to have," "to hold," "to control," and "to have in one's possession." Other possible options include "to be in charge of," "to be responsible for," "to have custody of," and "to be the legal owner of." Each of these phrases can be used in different contexts to convey a specific meaning or level of control over possessions or assets. Ultimately, the choice of synonym will depend on the speaker or writer's intended message and the specific context in which they are using the term.