• (RP) IPA: /ˈlɒɡəhɛd/
• (GA) IPA: /ˈlɔɡɚˌhɛd/, /ˈlɑ-/

loggerhead (plural loggerheads)

1. (obsolete) A stupid person; a blockhead, a dolt.

   Synonyms: Thesaurus:idiot

   • c. 1595–1596, W. Shakespere [i.e., William Shakespeare], A Pleasant Conceited Comedie Called, Loues Labors Lost. […] (First Quarto), imprinted in London: By W[illiam] W[hite] for Cut[h]bert Burby, published 1598, OCLC 61366361 ↗, [Act IV, scene iii] ↗:

     Ah, you whoreſon loggerhead, you were borne to do me ſhame.

2. A metal tool#Noun|tool consisting of a long#Adjective|long rod with a bulbous end#Noun|end that is made hot#Adjective|hot in a fire#Noun|fire, then plunge#Verb|plunged into some material#Noun|material (such as pitch#Noun|pitch or a liquid) to melt#Verb|melt or heat#Verb|heat it.
3. (nautical) A post#Noun|post on a whaling#Noun|whaling boat used to secure the harpoon#Noun|harpoon rope#Noun|rope.
   • 1851 November 13, Herman Melville, “The First Lowering”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, OCLC 57395299 ↗, pages 245–246 ↗:

     Not very far distant Flask's boat was also lying breathlessly still; its commander recklessly standing upon the top of the loggerhead, a stout sort of post rooted in the keel, and rising some two feet above the level of the stern platform. It is used for catching turns with the whale line. Its top is not more spacious than the palm of a man's hand, and standing upon such a base as that, Flask seemed perched at the mast-head of some ship which had sunk to all but her trucks. But little King-Post was small and short, and at the same time little King-Post was full of a large and tall ambition, so that this loggerhead stand-point of his did by no means satisfy King-Post.

4. (botany, Midlands, dialectal, often, in the plural) A thistle-like flowering#Adjective|flowering plant#Noun|plant of the genus Centaurea, particularly the common knapweed (Centaurea nigra).
5. (zoology) Used as the name of various animals with large head#Noun|heads.
   1. The loggerhead duck or Falkland steamer duck (Tachyeres brachypterus; formerly Tachyeres cinereus), a species of steamer duck endemic to the Falkland Islands.

      Synonyms: logger duck

   2. The loggerhead kingbird (Tyrannus caudifasciatus), a bird endemic to the Caribbean and West Indies.
   3. The rufous-tailed flycatcher (Myiarchus validus), a bird endemic to Jamaica.
   4. The loggerhead shrike (Lanius ludovicianus), a bird endemic to North America.
   5. The loggerhead musk turtle (Sternotherus minor), a large-headed turtle endemic to the United States.
   6. The loggerhead sea turtle or loggerhead turtle (Caretta caretta), an oceanic turtle found throughout the world.
      • 1791, Oliver Goldsmith, “Of the Tortoise, and Its Kinds”, in An History of the Earth, and Animated Nature. [...] In Eight Volumes, volume VI, new edition, London: Printed for F[rancis] Wingrave, successor to Mr. [John] Nourse, […], OCLC 877622212 ↗, part IV (Of Crustaceous and Testaceous Fishes), page 361 ↗:

        The Loggerhead is ſo called from the largeneſs of its head, which is much bigger in proportion than that of other kinds. The fleſh of this alſo is very rank, and not eaten but in caſe of neceſſity.

• French: tyran à queue rousse