Loggerhead

Noun

1. A stupid person; a blockhead, a dolt.
2. 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.
3. A post on a whaling boat used to secure the harpoon rope.
4. A thistle-like flowering plant of the genus Centaurea, particularly the common knapweed (Centaurea nigra).
5. Used as the name of various animals with large heads. The loggerhead duck or Falkland steamer duck (Tachyeres brachypterus; formerly Tachyeres cinereus), a species of steamer duck endemic to the Falkland Islands.