The word "headed" is the past tense of the verb "head," which means to lead, to direct, or to move in a certain direction. In a more specific context, "headed" can refer to being in charge of a group or organization, or it can simply mean to be going towards a particular destination. When someone says, "I am headed to the store," it means they are on their way there.
The word "headed" derives from the Old English "heafod," which means "head" and has roots in Germanic languages. The verb form can be traced back to the 14th century, when it was used to denote guiding or leading.