A legal entity name is a term that refers to a group of real people, called natural persons, that acts as one entity for legal matters. Examples of such legal matters include contracts or lawsuits. Legal entities include corporations, unions and political parties.
These types of groups are commonly seen in instances where people take up class-action lawsuits against organizations of manufacturers. Another instance where "legal entity" could apply is when each member of a band signs a record contract; they are acting as the entity of the band name when entering the contract.
Legal entities do have limitations. They can't vote or hold public office.