An unintelligent person.
The loggerhead duck or Falkland steamer duck (Tachyeres brachypterus; formerly Tachyeres cinereus), a species of steamer duck endemic to the Falkland Islands.
The loggerhead kingbird (Tyrannus caudifasciatus), a bird endemic to the Caribbean and West Indies.
The loggerhead sea turtle or loggerhead turtle (Caretta caretta), an oceanic turtle found throughout the world.
A thistle-like flowering plant of the genus Centaurea, particularly the common knapweed (Centaurea nigra).
The loggerhead musk turtle (Sternotherus minor), a large-headed turtle endemic to the United States.
A metal tool consisting of a long rod with a bulbous end that is made hot in a fire, then plunged into some material (such as pitch or a liquid) to melt or heat it.
The loggerhead shrike (Lanius ludovicianus), a bird endemic to North America.
The rufous-tailed flycatcher (Myiarchus validus), a bird endemic to Jamaica.
A post on a whaling boat used to secure the harpoon rope.