noun, plural: heads
(1) The cephalic part of an organism, especially the body part containing the brain and/or most organs used for feeding and/or sensing
(2) The topmost part of an object
In most animals and humans, the head is the uppermost part of the body where brain, eyes, ears, nose, and mouth are located. The human head (relative to body) is regarded as the largest among other animals.
In some animals, the head is not found on the topmost (anterior) part of their body. For instance, the squids have head-foot in which their arms and tentacles are located. Other animals such as sea stars have no distinctive head. Sea stars have eyespots at the tip of the arms, mouth at the center, and no centralized brain.