1. Referring to or relating to someone who has an important official title, rank, or position; but who has no real power or authority to exercise the functions usually associated with it: "The king was the titular head of the country; however, the prime minister had the political power."

"She is the titular head of the family."

2. Derived from or figuring in the title of a work; such as, a book or a movie: "He had a titular role in a movie."
3. Etymology: from Latin titulus, "title".

Not having a title or not existing in name.

1. A person who is in an official position of leadership and who possesses few, if any, actual powers.

Sometimes such a person may be in a position of titular leadership and yet exercise more power than would normally be expected, because of his or her personality, popularity, or experience.

A titular ruler or a titular head is not restricted to political leadership, but it can also refer to an organization; such as, a corporation, an industry , a government position, or any other group.

2. Etymology: Formed from a combination of the Latin titulus, "title" and the English suffix -ar, which means "of" or "belonging to".