loggerhead

noun

1. 1.A stupid person; a blockhead, a dolt.
2. 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. 3.A post on a whaling boat used to secure the harpoon rope.
4. 4.(often in the plural) A thistle-like flowering plant of the genus Centaurea, particularly the common knapweed (Centaurea nigra).
5. 5.Used as the name of various animals with large heads.