Apparent heir, a term used to describe someone who is believed to be next in line to inherit a title or estate, has several synonyms. One of the most common is "presumptive heir," which carries similar connotations of being the likely successor but also implies a level of uncertainty or potential challenge to their claim. Other synonyms include "heir apparent," which is a more formal and definitive term, and "designated heir," which suggests that the individual has been specifically chosen for the role. "Putative heir" is another option, although this term is more often associated with cases of disputed or contested inheritance.